- Address review feedback: change return type of RANGE_SEQ_IF::next()

pointers.

- Make Mrr_ordered_index_reader() save the rowid across scan interruptions

Also
- Fix compiler warning for setup_buffer_sizes()
- Add commented key_copy/key_restore for better handling of a similar issue
  with index record being destroyed by scan interruption (which causes 
  incorrect evaluation of pushed index condition later on).

Fixed compiler warning

mysql-test/r/named_pipe.result:
  Fixed test results for windows builds
mysql-test/r/shm.result:
  Fixed test results for windows builds
sql/item_cmpfunc.cc:
  Fixed compiler warning about uninitialized "first"

Problem : mtr reports test failure because it sees
[ERROR] mysqld got exception 0x80000003 ;
in the .err file

The exception comes from DBUG_EXECUTE_IF (.. abort())

Fix:  use DBUG_ABORT instead of abort() - it does not throw 
any exceptions.

The reason for failure is that DBUG_EXECUTE_IF in mi_open()
only worked for Unix-formatted file names, due to strstr(name, "/crashed")

The fix change strstr() above to strstr(name, "crashed"), to it can work with 
Windows file names as well.

 
Reason: inconsistent compilation, federatedx is compiled without SAFEMALLOC
flag, while anything else is compiled with SAFEMALLOC.

As a consequence, my_hash_init used inside federatedx initialization does not
provide correct caller info parameters (file, line) , so they are initialized with 
whatever is on stack. When info about allocated memory is output in
COM_DEBUG command, the server crashes trying to output string starting at
0xcccccccccccccccc.

The fix is to remove SAFEMALLOC  preprocessor flags 
from every CMakeLists.txt, except the top-level one.

Also, SAFEMALLOC is not defined by default now, instead
there is WITH_DEBUG_FULL CMake option which adds 
-DSAFEMALLOC to C and C++ flags in debug compilation. 
This option is off by  default, because 
1) Debug C runtime already has heap debugging builtin with 
 overwrite and leak detection
2)safemalloc considerably slows down the tests.


Note also  that 
- SAFEMALLOC is gone  in MySQL5.5
- On Windows, heap related overflows can also be found using free pageheap utility
(that is also part of application verifier). This is even more efficient if there are no other layers 
on top of Windows heap allocator, e.g  it is most efficient with release version.

- Fixed problem with oqgraph and 'make dist'

Note that after this merge we have a problem show in join_outer where we examine too many rows in one specific case (related to BUG#57024).
This will be fixed when mwl#128 is merged into 5.3.

- Moved end_pagecache() to after maria_close()
- Flush page cache before closing files (in maria_pack)
Fixed test suite failure for PBXT

mysql-test/suite/pbxt/r/select.result:
  We mask out the 'rows' column because it may differ from run to run
mysql-test/suite/pbxt/t/select.test:
  We mask out the 'rows' column because it may differ from run to run
storage/maria/maria_chk.c:
  Moved end_pagecache() to after maria_close() to not trigger end-consistency testing of pagecache.
storage/maria/maria_pack.c:
  Moved end_pagecache() to after maria_close() to not trigger end-consistency testing of pagecache.
  flush page cache before closing files.

The assert removed because it do not take into account case when previous and this buffers used for first time but previous buffer was not sent to disk yet (i.e. previous buffer was never sent to disk yet).

The Aria multithread test unlocked.

storage/maria/unittest/ma_pagecache_consist.c:
  Fixed pagecache shutdown.
storage/maria/unittest/ma_pagecache_rwconsist.c:
  Fixed pagecache shutdown.
storage/maria/unittest/ma_test_loghandler_multithread-t.c:
  The Aria multithread test unlocked.
storage/maria/unittest/ma_test_loghandler_pagecache-t.c:
  Fixed pagecache shutdown.

(Not critical, we will just catch the error later)

Added missing inc_counter_for_resize_op(pagecache).
(caused maria.maria-preload.test to fail)

storage/maria/ma_loghandler.c:
  Fixed compiler warning
storage/maria/ma_pagecache.c:
  Added missing inc_counter_for_resize_op(pagecache).
  (caused maria.maria-preload.test to fail)

Fixed timing test failures.
Fixed a failure in the Aria engines page cache and log handler (found with maria.maria-big test)
- This could cause a core dump when deleting big blobs.
- Added test to end_pagecache() to verify that page cache was correctly used.
  - inc_counter_for_resize_op and dec_counter_for_resize_op are called same number of times.
  - All page cache blocks was properly deallocated (empty)


mysql-test/suite/innodb/t/innodb_bug38231.test:
  Fixed timing issue (code comment says it all)
mysql-test/suite/innodb_plugin/t/innodb_bug38231.test:
  Fixed timing issue (code comment says it all)
sql/debug_sync.cc:
  Fixed compiler warning
storage/maria/ma_loghandler.c:
  Fixed bug found by maria.maria-big test:
  - Fixed race condition between update thread logging a very big blog and checkpoint thread.
storage/maria/ma_pagecache.c:
  Added assert to ensure mutex was properly locked.
  Added test to end_pagecache() to verify that page cache was correctly used.
  - inc_counter_for_resize_op and dec_counter_for_resize_op are called same number of times.
  - All page cache blocks was properly deallocated (empty)
  In pagecache_delete_internal(), properly reset counters and pins if functions aborts.
  Added missing inc_counter_for_resize_op() to pagecache_wait_lock().
  Added missing dec_counter_for_resize_op() to pagecache_delete()

- Testcase (but iself is no longer repeatable)

- Testcase (the bug itself was fixed by development on BKA side)

- Address Monty's review feedback, part 6: rename "handler *h" variable in all
  DS-MRR classes to something else.