Regularize usage of Utils.WithAsInstanceOfOpt
Regularize usage of EclipseUtils
constrain EditorUtils
Merge pull request #226 from huitseeker/pre/UtilsAPI

Cleanups as prelude to Utils API
Moves to sdt version of syntax Category
Adapts to generic syntax colouring preference page
Adapts to ScalaSyntaxClass cleanup
Adapts to the new syntax parsing API
Adapts to RegionUtils API changes