Clarifies findWord doc
Creates a generic preference page for syntax colouring

With some initial reorganization of code.
Cleans up ScalaSyntaxClass
Creates an API for the syntax parsing support

The API classes were split of the implementation and moved in core.lexical.
Makes RegionUtils part of the API

Moves to util.eclipse
Adds documentation
Adds/updates tests
Improves code scanners and partitioners doc
Merge pull request #811 from skyluc/issue/API-Syntax

Issue/api syntax