add sprites.png (toolbar icons sprite)
 * icons from http://fontawesome.io/, converted to png using http://fa2png.io/
 * Licensed under SIL Open Font License (http://scripts.sil.org/OFL)
 * sprite generated using imagemagick 'convert *.png +append sprites.png'
update COPYING for icons
add icons to header buttons and CSS for sprites
Merge branch 'toolbar-icons' into telecom

Conflicts:
	tpl/page.header.html