Added DBUG_ASSERT() to unlikely error senario
Don't use errno == 0 in maria_create() / myisam_create()

sql/sql_insert.cc:
  Added DBUG_ASSERT() for case that should never happen in real life
  Added my_error() to avoid assert if mysql_lock() or postlock() doesn't call my_error()
storage/maria/ha_maria.cc:
  Log queries to maria_log if compiled with EXTRA_DEBUG
storage/maria/ma_create.c:
  Don't use errno == 0
storage/maria/ma_loghandler.c:
  Added logging of debug info to maria_log
storage/maria/ma_loghandler.h:
  Added logging of debug info to maria_log
storage/maria/ma_recovery.c:
  Added printing of debug info from maria_log
storage/maria/trnman.c:
  Added functions to read/store state in TRN
storage/maria/trnman.h:
  Added functions to read/store state in TRN
storage/maria/trnman_public.h:
  Added state in TRN to remmeber if we have already logged the query
storage/myisam/mi_create.c:
  Don't use errno == 0