Button Re-write

This replaces PR #1216 

This includes new widget controlgroup which replaces buttonset
Current known issues 
 - [x] Checkboxradio testfailure missing default element (@scott_gonzalez said it should not have one because it cant be sane ) this causes common tests to fail
 - [ ] Backcompat
 - [x] Controlgroup icon only buttons 1px too short in chrome, firefox extra weird @jaspermdegroot think you could take a look?
 - [x] demos/controlgroup/default.html As above, labels should demo something
 - [x] demos/checkboxradio/default.html doesn't have the "command line" anymore, but still doesn't look like a demo. Labels should reflect some real world usecase.
 - [ ] demos/button/icons.html still looks like a visual test, not a demo

Yes the current way is much much faster. Selectors work right to left so your way it would first select all ":ui-button" then filter for `.ui-button` which actually would defeat the purpose of `.ui-button` in the selector at all. 

this selects `ui-button` ( a much faster selector ) then filters `:ui-button` to make sure they are widgets and not css only buttons.