Less: "@import (less) "file.css"" throws exceptions when changing the including file

[heldchen]

since less 1.4.0 (https://github.com/less/less.js/blob/master/CHANGELOG.md#140-beta-1--2) it is now possible to specify how a file included with @import should be handled:

You can specify options on imports to force it to behave as css or less @import (less) "file.css" will process the file as less"

when having the statement @import (less) "file.css" in a .less file, any keypress in the editor window will throw the following tow exception:

An internal error occurred during: "Xtext validation".
java.lang.IllegalStateException: No IResourceServiceProvider found in registry for uri file.css

[vtst]

This is in fact the same problem as issue #164.