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
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”.
Merge pull request #920 from madmatt/pulls/behat-image-uploads

Fix behat tests for insert-an-image.feature
Merge pull request #921 from madmatt/pulls/behat-insert-links

Fix behat tests for insert-a-link.feature
Merge pull request #946 from srizzling/adminasset-filter

Adding AdminAssets filter Behat tests
Merge pull request #951 from sheadawson/950-fileexists

FIX fileexists check
FIX Fixes #965. Allow user date-settings to show on GridField Page admin

- Relies on framework PR #2961.