update(docs): improved descriptions for layout attributes
fix(styles): remove global table leak, move into demo, remove main.scss
release: version 0.5.1
chore(): update changelog for 0.5.1
docs(theming): add information about md-theme-watch
update(interimElement): added support for  callback in the show() API
enhance(demos): dialog demo uses  callback. Improved subheader styling
update(build): changes to support debugging tests and karam 0.12 API

API 0.12 now uses `module.export = function(config) {...}` in karma.conf.js
Interactive debugging of karma tests now supported in WebStorm.
update(tests): tests $mdDialog onComplete callback option

Refs #518
update(tests): dialog tests confirm arguments passed to onComplete.
update(docs): added onComplete usage to $mdDialog sample
docs(mdDialog): add locals to usage example
test(md-slider): Coverage for ARIA attributes