- Reduced memory requirements for mysqltest to 1/4.th  This also gave a speedup for 5x for some tests.
- Reduced memory usage from safe_mutex.
- Fixed problem with failing tests that could not restart mysqld becasue the port was reserved
- More DBUG information
- Fixed bug where bitmap_set_prefix() wrote over buffer area.
- Initialize n_pages_flushed in xtradb which was used uninitialized.

client/mysqltest.cc:
  Reduced memory usage (400K -> 80 for simple test;  400M -> 70M for some other tests)
  - Smaller dynamic arrays at start
  - Made 'st_connection' significantly smaller by allocation 'mysql' on demand in mysql_init() and storing require_file in a mem_root.
  - Fixed that when one does --debug we get information from safemalloc in the trace
  (Most of changes are changing &connect->mysql to connect->mysql
libmysql/libmysql.c:
  Don't call mysql_thread_end() if my_init() was called outside of mysql_server_init()
  This is needed to get information from my_end() into the DBUG log
mysql-test/README:
  Fixed wrong comment
mysql-test/mysql-test-run.pl:
  Reserv 20 ports / mysql-test-run thread.
  (Needed as some tests uses 9 mysqld servers)
mysys/hash.c:
  More DBUG information
mysys/my_bitmap.c:
  Fixed bug where bitmap_set_prefix() wrote over buffer area.
mysys/safemalloc.c:
  More DBUG information
mysys/thr_mutex.c:
  Initialize smaller arrays be default.
sql-common/client.c:
  More DBUG_PRINT
storage/xtradb/srv/srv0srv.c:
  Initialize n_pages_flushed which was used uninitialized.