Language change implementation revamped. Didn't work as intended with Arduino IDE.
Fix spacing
Using the new language implementation wasn't behaving as expected.

No matter what LANGUAGE_CHOICE was set to it would always take the en branch.
I revamped it a bit to use a macro to create the language include file name. This required a slight tweak to the RU declaration since it's special-cased in a couple places in code.

This is an attempt to pull my changes from #1222 over.
Fix spacing
Merge branch 'LanguageFix' of github.com:RobotCaleb/Marlin-Kossel_Clear into LanguageFix

Conflicts:
	Marlin/language.h
Merge pull request #1267 from RobotCaleb/LanguageFix

Language Fix - Using the new language implementation wasn't behaving as expected.