Modify Gruntfile to convert LESS to SCSS

TODO:
 - Fix mixins/hooks
Refactor variables.less to avoid undefined in SCSS
add @base-code-font-family to variables.less to fix normalize compile in SCSS
add grunt-text-replace
ignore .sass-cache
Merge remote-tracking branch 'upstream/master'
extended grunt file for mixin-calls and @keywords they were missing
Moved hooks to top of less files (needed for SASS)