filters.js -- to_string does not check for null/undefined inputs
remove strict checking of null/undefined
Merge pull request #31 from karthik25/sys-index-err

filters.js -- to_string does not check for null/undefined inputs
Update to version 0.19.0
ability to export collections, import coming soon!
import safe json generation
fully functional export
Merge branch 'collection-import' of https://github.com/karthik25/mongo-express into collection-import