polymer-ui-menu: remove unneeded attributes/properties since they are
inherited from polymer-selector already
make tab inline-block
polymer-ui-arrow: set borderWidth in update() along with other style
changes.
ready -> created; inserted -> enteredDocument
polymer-ui-submenu-item: remove attribute that is no longer needed
make polymer-ui-icon function on Firefox with minimal expense
set default value to false to indicate it's a boolean attribute
add example
polymer-ui-overlay: set boolean props to false
remove extra "
Merge branch 'master' of github.com:Polymer/polymer-ui-elements
Merge remote-tracking branch 'upstream/master'