Update rdoc 4.0 to 4.1
Rid off duplicated to_json #72
Update database/mongo.md

* collections return as JSON
* return false if object does not exist
Merge pull request #90 from sinatrasapporo/to_json

Rid off duplicated to_json #72
Merge pull request #91 from sinatrasapporo/databases

Update database/mongo.md
Merge pull request #88 from sinatrasapporo/rdoc-4.1

Update rdoc 4.0 to 4.1
Update AssetPack recipe to use Foundation 5