search: add directive for endless scrolling

the directive will check whether the element is visible in viewport.
directive: minor improve directive
adjust search result layout
add search page sass file
adjust line hieght for search content title
search: appearance minor change
search: add sponsors name
search: add spinner
search: one more spinner
default hide sidebar
add substeps for progress bar in bill page, but...
Merge branch 'master' of https://github.com/g0v/ly.g0v.tw
change sidebar to mobile-hide
fix substeps with ng-click
toggle substeps
fix toggle
add css spinner

inspired by
http://www.designcouch.com/home/why/2013/05/23/dead-simple-pure-css-loading-spinner/
use css spinner

the gif file has background color
search: stop scrolling detection if fetch whole results
+icons, nets.png