Extended configurability for colors, etc

Extended the configurability of the theme. The colors of the theme,  an optional amount of social network links and address lines can be easily set and configured straight from the config file. 
For this, the files had to be slightly rearranged, since the css files with variables need to in the /_include directory for them to be built properly.

If you approve to my changes, please pull this request to your repo and feel free to add me as a contributor!