3654: add "combine selections" option to project#show page.
3654: add selection dropdown to collections pages
3654: remove "Combine selected collections and files into a new collection" option from clippy.
Merge branch 'master' into 3654-combine-selections
Merge branch 'master' into 3654-combine-selections
3654: add integration and funtional tests for combining collections and collection contents.
3654: add selection dropdown to collection#show page
3654: add selection dropdown to collections page
3654: add selection dropdown to collections page
Merge branch 'master' into 3654-combine-selections
3654: test update
3654: add selection dropdown to collections page
3654: combine options is enabled when only data collections are selected in project view.
3654: use POST method to combine selections.
3654: little cleanup around the post method
3654: slight update to redirect to newly created collection
Merge branch 'master' into 3654-combine-selections
3654: redirection to newly created collection is now working.
Merge branch 'master' into 3654-combine-selections
Merge branch 'master' into 3654-combine-selections