Refined file upload/download/listing filter guards & routes

1. hacked jquery-file-upload-middleware to have it call next() upon
finishing, pass in empty function for listing/delete operations, and
removeIfNoRelatedRecord() for post operation. This is due to mech
collision in formidable and I/O database op in node/express.
2. break findOne filter into grabModel, grabKey and findOne.
3. defined filters for general logic apis.
Priorities:
a. Report data/file api signature automatically to 'Resource'
b. implement mutex filter.
c. various //TBIs in code.