Added the rollback_all paremeter into DB::rollback_transaction()
Merge pull request #638 from ose1955/1.8/develop

Nested transactions - rollback_all
documented --testsuite switch; related fuel/oil#228
corrected Mongo_Db like() docs; related fuel/core#1672
documented the new to_csv() $headings argument; related fuel/core#1611
Documented list_collections(); related fuel/core#1675
documented match_collection; related fuel/core#1655
documented the optional parameter for CSV format parsing; related fuel/core#1630
documented native session emulation