TagField should only render options if the lazy load value isn't set. Options from here come from subsequent POSTs, and rendering the options for every request significantly slows down both the form generation and render.
TagField hydrates the entire result set because a parent class calls `toArray()` on the $source.
This fix changes the source to an empty array, so no such manipulation can be made.
* Added parameter to SilverStripe\TagFieldTagField::__construct()
* Modified SilverStripe\TagFieldTagField::getOptions() to use assigned title field
* Modified SilverStripe\TagFieldTagField::getValue() to use assigned title field
* updated the CSS of the tag field to match with
the dropdown fields / list fields
* resolve with of the field to the style attr of
dropdown
* added style width
* removed the empty lines
* changed to the correct classname readonly tag field
* fixed the tag field signature
* removed the whitespace ending in line 352
As jQuery is bundled in the frameworks vendor.js having
these calls causes a duplicate of the jQuery library
This also means plugins link with the wrong library etc.
Noticed with `jQuery.dialog()` from a Page edit screen
going to an associated DataObject edit screen
* Update composer constraint and branch alias to support SS4 testing
* Add namespaces, update DataList quirk with getSourceList
* Add PSR-4 autoloader definition
* Move template to correct namespace location, update requirement paths
* FIX Visibility on allowed actions
* FIX Update chosen class names to match updates in framework
* Update Travis configuration for 4.x builds. Update docs for namespaced classes.
* Use "4" for the release instead of master.
* FIX Selected tag height. Move Readonly to own class.
