Fixes for the remaining 'not-yet-fixed' bugs found by Guilhem when running all tests with maria engine and one bug in maria_pack reported by Martin:
- Fix that query cache works with Maria
- Fixed wrong calculation if min_key_length which casued some tables to assert in insert if key contained NULL
- Restore auto_increment value if insert statement fails
- Fixed rare bug that caused crash in maria_pack if buffer was flushed at wrong point in time


configure.in:
  Added maria extension to distribution
mysql-test/r/maria.result:
  More test cases to cover bugs found by Guilhem
mysql-test/t/maria.test:
  More test cases to cover bugs found by Guilhem
storage/maria/ha_maria.cc:
  Fix that query cache works with Maria
storage/maria/ma_blockrec.c:
  Removed duplicate functionallity (already done in ma_pagecrc.c)
storage/maria/ma_create.c:
  Fixed wrong calculation if min_key_length which casued some tables to assert in insert if key contained NULL
storage/maria/ma_key_recover.c:
  Restore auto_increment value if insert statement fails
storage/maria/maria_def.h:
  Added variables to track auto_increment changes to be able to restore it in case of duplicate key
storage/maria/maria_pack.c:
  Fixed rare bug that caused crash if buffer was flushed at wrong point in time
storage/maria/unittest/ma_test_all-t:
  Added option --abort-on-error
  Ordered help message