adding new polymer log
polymer element
clean up based on Bobby comments
added show card to log and cleaned up some code where we had duplicate show calls
added scroll
made some updates based on bobby comments
Merge pull request #615 from mozilla-appmaker/new-log

New log
Ability to add/remove elements, and sort them (no top/middle/bottom working yet).
small fixes
Merge pull request #617 from secretrobotron/designer-component

Ability to add/remove elements, and sort
merge fix