Merge pull request #330 from bkng/release-1.20

PLFM-1778: fix limit offset ordering for getAllSubmissions()
urlencode encrypted session token (and urldecode before decrypting)
Merge branch 'develop' of https://github.com/Sage-Bionetworks/Synapse-Repository-Services into develop
from code review
from code review
change token to #!
Merge pull request #332 from jay-hodgson/develop

PLFM-1771: fix registration issue (and clean up old widget descriptors)
ability to create a single filehandle, and explicitly set it's content type
from code review
Merge pull request #333 from jay-hodgson/develop

ability to create a single filehandle, and explicitly set it's content type
:)
PLFM-1731 - add external URLs to provenance
merge upstream changes
small test change
:(
added test
Merge branch 'PLFM-1709' into PLFM=1709-d
Merge pull request #335 from john-hill/PLFM=1709-d

Plfm=1709 d
meaningless
:)