Updates mongodb driver sync/drop
Updates mongodb driver sync/drop

- .clear() no longer drops
- .drop() now drops without calling .clear()
- .sync() creates collection with some indexes

kolonse/node-orm2,benkitzelman/node-orm2,mariamjpinto/node-orm2,benkitzelman/node-orm2,hallta/node-orm2,locomote/node-orm2,kolonse/node-orm2,stueynz/node-orm2,kapouer/node-orm2,benkitzelman/node-orm2,kapouer/node-orm2,kolonse/node-orm2,ScoutGroup/onionrm,pskucherov/node-orm2,jtrinc/node-orm2,kapouer/node-orm2,dresende/node-orm2