Improved all functions that should check for MONGO_OK to be sensitive to failure. Added code so that functions which before simply returned void not return at least in an int with MONGO_OK or MONGO_ERROR. And finally added code for functions which return a gridfs_offset now will have the ability to return a value indicating partial completion of the work in case there was a prior failure on a function that required MONGO_OK
Merge pull request #125 from jsbattig/mongo-pull-gridfs-error-mgmt

Improved all functions that should check for MONGO_OK to be sensitive to...