change variable name to adapt to dashboard 2.0
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
replace data model with Mongoose
add indexes for clientId and userId
improve the work flow, auth code and access token will not be regenerated
added expiration flag
call attribute of accessToken after make sure it is not null
Merge branch 'ID-52' of https://github.com/Plypy/openmrs-contrib-id-oauth into Plypy-ID-52

Conflicts:
	views/consent.ejs
Merge branch 'Plypy-ID-52'