Merge pull request dselivanov#66 from dselivanov/master

small fixes to pass "R CMD check --as-cran"

fixing package build issues in case of missing mongoDB

Rd files updated with Roxygen

switching to jsonlite to solve some conversion bugs

version dump to 1.3.3.

Gerald removed from authors list to get back to CRAN

mongo.distinct including test is back to package

important notes for CRAN submission

small test bugfix

version dump