Only recent authors can publish a collab doc

Only users who recently editted a collaborative document can publish it.
This should avoid situations where a user who is only viewing a document
triggers a publication under his name even if he did not make any
changes himself.
Fixed up failing unit tests for publishing collaborative documents
Merged master into simong/collabdocs-recent-authors
Merged master into simong/collabdocs-recent-authors
add REST documentation to preview-processor module
add REST documentation for following module
move common models out of module
remove server from REST endpoint keys
remove server from REST endpoint keys
add REST documentation for discussions module
fix typo
alphabetize parameters
remove quotation marks from descriptions to keep parser happy
remove quotation marks from parameter descriptions to keep parser happy
use enum syntax for model parameters
use enum syntax in model parameters
convert form parameters to body parameters, remove quotation marks to make parser happy
convert multiple body parameters to single model
document string|array as array
fix typo