MDL-31830 course: improved course and category management pages
MDL-41394 course: management css is now in themes
MDL-41416 course management: converted category actions to action_menu component
MDL-31830 course: fixed management ajax config bug
MDL-41416 course management: converted listing actions to action_menu's
MDL-41393 course manage.php completely deprecated
MDL-31830 course: tidied up management support scripts
MDL-31830 course management: ajax loading of categories in the tree.
MDL-31830 course management: now allows drag and drop
MDL-31830 phpdoc: Cleaned up phpdocs and coding standard
MDL-31380 course management: minor fixes post peer-review from Andrew Davis

Thanks to Andrew Davis for spotting things leading to the following fixes
being made after his interface review:
* better handling of resorting
* Changed lang strings "resort" to "re-sort"
* Fixed typo in string for bulk move courses
* Fixed optional_param argument that needed to be array based.
* Fixed missing properties when re-sorting courses.
* dragdrop: fixed issues with viewmode
* theme_bootstrapbase: fixed management responsive CSS
* fixed navbar
* fixed category hiding bugs
* fixed category redirect
* improved notifications when moving categories
* clarified the wording when creating categories/subcategories
* simplified the display of show+hide icons
* now redirects after moving courses.
* fixed wording when a category contains no courses
* no longer selects a category by default
* fixed edit category URL
* tidied up capability checking
* fixed bug with toggling of create sub categories button
* view mode now possible with no selection
* fixed display of 999 per page
* fixed delete regression