Support both functions and regex transform types
Disable user selection in some parts of the layout
Update gulpfile to watch all JS files
Update a/an prefix to regex format
Add transform collections
Convert postfix -> suffix (more common word)
Show tag instead of label for prefix/suffix
Create node cache on vue init as well as on grammar update
Add jQuery context menu plugin
Change context menus to JS-based plugin

The new context menu works much better with deep nodes as it won't
continue outside of the page boundaries (it will right align when
there's not enough room for a submenu).

TODO: Reimplement add/update functionality
Reimplement adding/updating/removing sentence elements
Ensure element transform array is not empty
Fix issue with unhandled regexps in exported grammars
Fix swapped uppercase transforms
Fix slugify/constantify regexps
Lowercase transform labels
Restructure context menus
Refactor and sort context menus