added acknowledgement for fun-var-constraints
Merge branch 'develop' of https://github.com/stan-dev/stan into bugfix/issue-1151-fun-var-constraints
Merge branch 'develop' of https://github.com/stan-dev/stan into bugfix/issue-1151-fun-var-constraints
pushed ostream* through to variable constraints, resolving #1151
Merge branch 'develop' of https://github.com/stan-dev/stan into bugfix/issue-1151-fun-var-constraints
fixed mock model to use new 3-arg constraint
Merge pull request #1183 from stan-dev/bugfix/issue-1151-fun-var-constraints

Fixes #1151. Bugfix/issue 1151 fun var constraints