Add codeclimate and checkstyle to repos

[ianharrigan]

Add codeclimate to all relevant haxeui repos.

• [x] haxeui-core
• [ ] haxeui-openfl
• [ ] haxeui-flambe
• [ ] haxeui-kha
• [ ] haxeui-html5 - mostly working, regexp issue around method names
• [ ] haxeui-pixijs
• [ ] haxeui-nme
• [ ] haxeui-luxe
• [ ] haxeui-hxwidgets
• [x] haxeui-xwt

There is currently an issue with haxe-checkstyle not seeming to work on CC, but working with checkstyle locally is fine until this is resolved (https://github.com/HaxeCheckstyle/haxe-checkstyle/issues/320)

[ianharrigan]

@ibilon / @MSGhero - presumably you would prefer a different style for your backends, so ill leave that up to you... :)

[ianharrigan]

This is the issue on haxe-checkstyle: https://github.com/HaxeCheckstyle/haxe-checkstyle/issues/320

[ibilon]

Codeclimate/checkstyle added to haxeui-xwt.

haxeui-hxWidgets was already done but it didn't have the badges yet, added now.