#62 add compilation of helios.less to Gruntfile + grunt watch task

Originally at 2015-05-15T17:59:56Z by Manfred Kröhnert closed at 2015-05-15T18:06:40Z (pull request) Gruntfile now contains a task to compile .less to .css files (requires Grunt 0.4.5). In addition, a watch task is added to automatically do this step upon changes to helios.less (fix #40). Please merge this after #61 has been merged.