Added support for keeping a limited amount of documents in GridFS and removed the delete_old option.
Added support for keeping a limited amount of documents in GridFS and removed the delete_old option.

The delete_old removed all the old files while having a versioning system you might want to keep a limited set of files. This small little patch does that. You can specify a number of versions to keep by using the new versions option.

AndyObtiva/mongo-ruby-driver,jonhyman/mongo-ruby-driver,0x00evil/mongo-ruby-driver,pcarrier-packaging/deb-ruby-mongo,mongodb/mongo-ruby-driver,pcarrier-packaging/deb-ruby-mongo,ShanaLMoore/mongo-ruby-driver,pcarrier-packaging/deb-ruby-mongo,tommyb67/mongo-ruby-driver,jonhyman/mongo-ruby-driver,mongodb/mongo-ruby-driver,saghm/mongo-ruby-driver,agis-/mongo-ruby-driver,pcarrier-packaging/deb-ruby-mongo,aherlihy/mongo-ruby-driver,fairplace/mongo-ruby-driver,kay-kim/mongo-ruby-driver,wandenberg/mongo-ruby-driver,pcarrier-packaging/deb-ruby-mongo,estolfo/mongo-ruby-driver,xronos-i-am/mongo-ruby-driver,namusyaka/mongo-ruby-driver,dunedain289/mongo-ruby-driver,saghm/mongo-ruby-driver,brandonblack/mongo-ruby-driver,mongodb/mongo-ruby-driver,fhwang/mongo-ruby-driver,estolfo/mongo-ruby-driver,kay-kim/mongo-ruby-driver