Fixed failure in unittest/ma_test_loghandler_pagecache-t
Initialize pagecache callbacks explictily, not with pagecache_init().
This is to make things more readable and for the future to make more choices with callbacks


storage/maria/ha_maria.cc:
  Disable logging of index pages during repair
storage/maria/ma_bitmap.c:
  Initialize callbacks explictily, not with pagecache_init(), to make things more readable and for future to have more choices with callbacks
  Use new interface to flush logs from pagecache
storage/maria/ma_check.c:
  Fixed test for wrong keyblocks
  Use default functions to setup callbacks for pagecache
storage/maria/ma_loghandler.c:
  Use dummy functions for log flush callback (NULL doesn't work anymore)
storage/maria/ma_open.c:
  Initialize callbacks explictily, not with pagecache_init(), to make things more readable and for future to have more choices with callbacks
  Prefix external functions with _ma_
storage/maria/ma_pagecache.c:
  Use new simpler interface to flush logs if needed
storage/maria/ma_pagecache.h:
  Changed interface to a faster, simpler one to flush logs.
  Now we have a function that takes care of flushing logs, instead of a function to get lsn address
storage/maria/ma_pagecrc.c:
  Add functions for flushing logs
storage/maria/ma_recovery.c:
  Rename functions
storage/maria/maria_chk.c:
  Use default functions to setup callbacks for pagecache
storage/maria/maria_def.h:
  Prefixd global functions with _ma_
storage/maria/unittest/ma_pagecache_consist.c:
  Use dummy functions for log flush callback (NULL doesn't work anymore)
storage/maria/unittest/ma_pagecache_single.c:
  Use dummy functions for log flush callback (NULL doesn't work anymore)
storage/maria/unittest/ma_test_loghandler_pagecache-t.c:
  Use maria_flush_log_for_page to flush log pages. Fixes failure in unittest