2.9.0 CDN adoption, notifications refactor.

New feature

Many third-party front-end dependencies are now used from a CDN rather than included in uw-frame's build via Bower. ( #324 )

This involved tweaking the Gruntfile, package.json, and build.sh a bit.

Fixes

Fixes that might affect frame-based apps

• searchURL and the "What's New" URL in app-config.js are now relative rather than absolute URLs. ( #327 )
• fix for launch-button text-decoration ( #326 )
• Widget tooltips now stay within the visible canvas ( #331 )

Fixes that probably won't affect frame-based apps

• Major refactoring of notifications ( #323 ).
• Multiple popups are no longer bugged ( #330 ). There are no immediate use cases for multiple popups, especially since they're significantly interruptive, but if we do end up with multiple popups in the future, we won't trip over this bug.

Upgrading

The "new feature" of CDN usage earned this release a minor rather than patch version bump.

Upgrading should be seamless. Vanilla frame-based apps should see no practical change, since the same dependencies are still available, just loaded differently.