More C API bits.
rocksdb_options_set_min_level_to_compress
added rocksdb_readoptions_set_tailing
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Add rocksdb_writebatch_data to C API.
rocksdb_writebatch_count
C API for LiveFileMetadata.
Add rocksdb_delete_file to C API.
Merge remote-tracking branch 'origin/master'

Conflicts:
	db/c.cc
	include/rocksdb/c.h
Merge remote-tracking branch 'alberts/master'