Cleanup and use spaces instead of tabs in javascript files
Fix a small bug
Move layout logic in "settings" page to jade template.
Change the files structure of the compilers and file types.
Merge branch 'cleanup/use-spaces' into feature/make-compilers-modular

Conflicts:
	src/app/scripts/FileType.js
	src/app/scripts/compilersManager.js
	src/app/scripts/fileTypesManager.js
	src/app/scripts/jadeManager.js
	src/app/scripts/pages/settings.js
	src/app/scripts/renderpage.js
Add `FileManager` and use `path.join()` in-place of `a + path.sep + b`.
`FileManager` is responsible for all common paths and some file manipulation methods.