demo(sidenav): adde a component id to the example to make it work

Closes #338
docs(README): add period('.') to two sentences

Closes #329
chore(build): copy src sass files to dist for bower-material

Fixes #4. Closes #326.
docs(button): incorrect description

replace `radio button's text` by `button's text`

Closes #313.
feature(swipe): added Swipe service and directive

Sliders nested within swipeable containers no longer propogation slide events.
toast uses $materialSwipe service
Tab demo with external tab views now uses <material-swipe-left> and <material-swipe-right> directives.
Now uses 'material.core' module to run environment validations
code formatting improvements
Merge branch 'wip-swipe' of github.com:angular/material into wip-swipe

Conflicts:
	src/components/swipe/swipe.js
swipe now ignores `disabled` attribute