Page edit access with CMS_ACCESS_LeftAndMain (fixes #908)

"Access to all sections" implies edit access in the CMS
FIX: Changetracker causing 'saveButton is not a function' error

Regression from 1571d35
Fix “I can insert an image from the CMS file store”.
Fix behat tests for insert-an-image.feature

- Fix “I can insert an image from the CMS file store”.
- Remove unused scenario (we no longer support adding multiple images at once from the CMS).
- Fix “I can edit properties of an image before inserting it” scenario.
- Remove “I can edit dimensions of an image before inserting it” scenario - these fields no longer exist.
- Add documentation to explain why this scenario is marked @todo.
Fix behat tests for insert-a-link.feature

- Fix "I can link to a file" scenario.
- Fix "I can link to an anchor” scenario.
- Fix "I can edit a link” scenario.
- MINOR: Grammar fixes.
- Fix "I can remove a link” scenario.
Adding AdminAssets filter Behat tests
FIX fileexists check via ajax didnt know what folder the file was being uploaded to. Fixes #950
BUG Report admin don't listen to filters

It seems like filter params that are added to the url are added in a bad way

Currently

    ?0[name]=filters[ContentReviewOwnerID]&0[value]=1

Expected:

    ?filters[ContentReviewOwnerID]=1
Added min stability for composer

Required for scrutinizer runs
Merge remote-tracking branch 'origin/3.1'
Merge pull request #956 from stojg/reportadmin-bug

BUG Report admin don't listen to filters
Fixed behat image upload tests

Was using "File" class rather than "Image",
which broke HtmlEditorField->saveInto() with "unknown method getWidth()"
Merge remote-tracking branch 'origin/3.1'
Fixed behat image upload tests (contd.)
Merge remote-tracking branch 'origin/3.1'
Add PHP 5.6 to the test matrix
FIX: Reports with Parameter fields override ReportTitle and ReportDescription

Fixes #696
Merge pull request #911 from chillu/pulls/908-all-sections-canedit

Page edit access with CMS_ACCESS_LeftAndMain (fixes #908)
Merge pull request #917 from kinglozzer/savebutton-changetracker-issue

FIX: Changetracker causing 'saveButton is not a function' error
Merge pull request #919 from madmatt/pulls/behat-insert-image

Fix “I can insert an image from the CMS file store”.