Avoid recovery on _fdb_open if read-only mode
Avoid recovery on _fdb_open if read-only mode

This prevents tools like forestdb_dump from accidentally deleting
old file in the event of a crash if compaction had completed.

Change-Id: I5207219c4cb84665292f9c93981cb9cae9d5811f

couchbase/forestdb,jinxuan/forestdb,yyangpan/forestdb,hisundar/forestdb,joliss/forestdb,sushmaad/forestdb,yyangpan/forestdb,joliss/forestdb,zhaog/forestdb,hisundar/forestdb,sushmaad/forestdb,wurikiji/forestdb,wurikiji/forestdb,zhaog/forestdb,jinxuan/forestdb,couchbase/forestdb