e2e fix start_checkpoint before iterator_init
e2e fix start_checkpoint before iterator_init

The iterator can return docs that the test expects to be deleted
unless commit is performed before the iterator is initialized

start_checkpoint internally does a commit

Change-Id: I9131a9ced9f0028f1fc73b6fcaf52fe27d166c49

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