commit development & production copies of main stylesheet
move 'imagemin' subtask to 'build' task in 'Gruntfile.js'
update social networking font icons in <aside> (see msg)

change both GitHub and Google + font icons. reduce size for all icons.
update sprites (see msg)

-remove social network images as they've been replaced with Font Awesome font icons.
-remove code realted to social networking icons from 'grunt/cssSource/_retinaMediaQuery.scss'
-change background image size in 'grunt/cssSource/_base.scss.'