Allow setting of specific form actions that do not require validation

Move validation exemptions into CMSForm

Also fix buttonClicked() to skip CompositeField

Whitespace

Adding unit tests
FIX gridfield delete alert selector specificity
Merge pull request #2493 from kinglozzer/2449-form-validation-exemptions

NEW: Allow setting of specific form actions that do not require validation on CMSForm
Moved manage-files.feature to cms module
Updated Te Reo translations
Globalization in TreeDropdownField JS
Chinese translation encoding
Updated Te Reo translation
API: Pass extra context information to shortcode handlers.

This allows shortcodes to perform more complex actions on the element
which contains them. For example, the element reference can be used
to add extra classes or attributes to links which provide additional
metadata.
Merge pull request #2507 from ajshort/pull-3

API: Pass extra context information to shortcode handlers.
Merge pull request #2502 from colymba/fix-gridfield-delete-alert

FIX gridfield delete alert selector specificity