Made btree store creation (i.e. superblock creation) and metainfo initialization be done in one transaction.
Merge branch 'next' into sam_84
Merge branch 'next' into sam_84
Merge branch 'next' into sam_84
Merge branch 'next' into sam_84
Merge branch 'sam_demock' into sam_84
Introduced move_serializer_file_to_permanent_location and the practice of opening fresh serializer files in temporary locations (so that we do not leave partially initialized files around).
Made serializer_file_opener_t::unlink_serializer_file exist for the disk backed queue.
Mode move_serializer_file_to_permanent_location run in a blocker pool.
Made filepath_file_opener_t have reentrance_mutex_, made unlink_serializer_file run in blocker pool.
Made serializer_file_opener_t methods return void instead of pretending to return bool but actually crashing.
Made us use F_FULLFSYNC on OS X after call to ftruncate.
Merge branch 'sam_demock' into sam_84
Made the F_FULLFSYNC call on OS X after call to ftruncate actually compile!  *blush*
Added necessary string arguments to guarantee_err macros in disk.cc.
Removed stray debugf statements in branch sam_84.
Made things compile in SEMANTIC_SERIALIZER_CHECK mode.
Made us not run ::rename or ::unlink in a blocker pool in filepath_file_opener_t, because they broke stuff.
Removed stray debugf in disk.cc that announced openings of files.
Added recreate_temporary_directory function, for creating/wiping rethinkdb_data/tmp upon startup.