[PATCH] General update for CartoCSS syntax highlighting

Summary:
Hi.

Here I propose an updated syntax highlighting for CartoCSS. (I'm also the author of the original, currently used highlighting file.)

Changes:

• correct casing for CSS color names
• comment formating is tweaked
• do not use anymore a hardcoded list for properties. (These are evolving too fast to keep up.)
• much better highlighting for strings (data field syntax within strings is now highlighted, both in properties and comments)
• Overall the design fits better the structure of CartoCSS
• Better design for named instances, classes and so on

Test Plan: I've developed this code about a year ago and since then have been using it on my local machine when working with CartoCSS. Seems to work fine.

Reviewers: Framework: Syntax Highlighting, cullmann

Reviewed By: Framework: Syntax Highlighting, cullmann

Subscribers: cullmann, kwrite-devel, kde-frameworks-devel

Tags: Framework: Syntax Highlighting, Kate, Frameworks

Differential Revision: https://phabricator.kde.org/D27430