Now ma_test1 -M -T and ma_test2 -M -T produces readable, applyable logs

Note: The .MAD file is not binary identical after applying redo compare to a an original file.
(This is becasue we don't have full information which function called PURGE_REDO_BLOCKS).
To verify if a file was correctly applied, we now instead compare row checksums


BitKeeper/etc/ignore:
  added storage/maria/tmp/*
include/maria.h:
  Added maria_commit() and maria_begin() to be used with external tests
storage/maria/ha_maria.cc:
  Ensure maria_def. is read in C mode
storage/maria/ma_blockrec.c:
  Fixed redo handling.
  _ma_apply_redo_purge_blocks() updated to handle any number of purged blocks
  Removed code to make data file idenitcal after redo (can't easily be done). See changeset comments
  
  Now ma_test1 -M -T and ma_test2 -M -T produces readable, applyable logs
storage/maria/ma_commit.c:
  More DBUG statements
  Moved variable declaration to start of function (portability fix)
  Added helper functions 'maria_commit()' and 'maria_begin()'
storage/maria/ma_loghandler.c:
  Fixed wrong REDO_PURGE_BLOCKS initialization
storage/maria/ma_recovery.c:
  Added UNDO_ROW_UPDATE
  Removed wrong setting of lsn (there was no lsn at the used position)
  Fixed REDO_PURGE_BLOCKS to handle any number of blocks
storage/maria/ma_test1.c:
  Added transaction support (via maria_begin() & maria_commit()) to get a log that can be applied with maria_read_log
storage/maria/ma_test2.c:
  Added transaction support (via maria_begin() & maria_commit()) to get a log that can be applied with maria_read_log
storage/maria/ma_test_recovery:
  Create temporary files in maria/tmp
  Verify files with checksums instead of byte comparisons
storage/maria/maria_chk.c:
  When using with -dss we only get  filename, records and checksum.
  This is useful to do a quick comparision if a files is identical to another one.
storage/maria/maria_def.h:
  Added ma_commit()
storage/maria/maria_read_log.c:
  Added --help