Remove old, unused dashboard_section helper
Deep copy the filters hash.

Filter :if and :unless options were being deleted and thus only
used for the first request.

Deep copy of the filters hash allow safe deletion of filters' options
like :if and :unless, to pass a clean set of options down the line.
Merge pull request #2523 from PChambino/patch-1

Don't delete :if and :unless from filters
move installation instructions out of the README

by removing duplication it's easier to keep it updated
reword part of the README
update README so the sentence fits on a single line
use shields instead of badgr for Gittip badge