Bumped version to 4.0.0.
The keyword 'requires' is no longer shown as keyword

The parsing is done by Scalariform. Because it treats 'requires' still as a keyword,
it needs to be translated to default content type.

Fix #1000750
Reformatting of ScalariformToSyntaxClass
Merge pull request #302 from dragos/bump-master-version

Bumped version to 4.0.0.
Merge pull request #305 from sschaef/issue/requires-keyword

Issue/requires keyword