add quiet_assets gem
catch error when exception raised in Favorite/Retweet.from_json
precompile assets: add *.css and *.js
don't add digest to precompiled assets filename
precompile *.js
use bootstrap-sass
reorganize asset files
Revert "don't add digest to precompiled assets filename"

This reverts commit ad2193eddddae6afd013bac2f3d49bd89eca1217.
remove unused stylesheet_link_tag
change Sass syntax: ":prop option" -> "prop: option"
fix single tweet importing
improve (Tweet|Favorite|Retweet).from_json
improve tweet views: click fav/rts count to show full; move import link
update collector's em-twitter (0.3.3)
remove unused style from tweets.css.sass