updates readme with grunt-cli install instructions
removes orphaned CSS blocks from base and 500 templates
removes bower and grunt dependency from package.json

should be installed as global modules
updates grunt configuration

adds cssmin, restructures production and development dependencies
adds DEBUG_STATIC condition for assets in base template

default = False; for devs prefering debug-friendly non-minified
staticfiles
adds production-ready assets to repository

for base.html template