demo(build): make build modal download consistent

Closes #1579
fix(datepicker): remove unneeded date creation

Closes #1595
docs(README): add a Bitdeli badge

Closes #1605
refactor(accordion): use optional binding for `isOpen`

Closes #1596
refactor(carousel): use optional binding for 'active' attr in slides

Closes #1602
refactor(carousel): remove unneded  dependency
refactor(tooltip): remove work-arround for AngularJS 1.0.x bug
refactor(dropdownToggle): listen to `$locationChangeSuccess`

 * Listen to  event instead of adding an extra `$watch` to the `$digest` cycle.
 * Remove `$location` DI, that sometimes caused weird issues.

Closes #1585
demo(all): indicate that we depend on AngularJS 1.2.x