Ported/finished UseNewKeyword.

Ported/edited from original code action implementation to code issue.
Added missing types/override checks to New.
Updated project file.
Fixed coding style.
Fixed project line endings.
Merge pull request #418 from TheCommieDuck/roslyn-new-modifier-issue

Added 'CS0108UseNewKeywordIfHidingIntendedIssue' and tests.