remove about vc
update app icon image
update Launch Image
replace app icon 60 px to 80 px
command vc: set web view background color
topic list vc: set right sync buton color
topic list vc: change navigation bar buttons color
topic list vc: change navigation bar color
button category: remove color and increase font size
doc css: upgrade to sketch
update constraints
storyboard: update fontsize
storyboard: update label text color
topic vc: update picker view label
topic vc: change picker view content size
topic vc: set picker view background color
console vc: udpate close button
remove useless class
topic vc: customize selection indicator lines

We cannot custom our own picker view selection indicator since ios7 (
cf: http://goo.gl/KjxaXd )
We choose to hide those two selection lines by adding two subviews to
the controller view
with the same background color than the picker view.
By doing this, we will create a mask effect on built-in selection
indicators and avoid their appearance
cosmetic changes