peaks.js standalone builder

- waveform-data.js@1.3.0
- added back the requirejs build system
- replaced `grunt-bower-install` by `grunt-wiredep`
- removed the unneeded requirejs dependency
Build system overhaul

- removed `grunt-open` by using the `open` property of `grunt-contrib-connect`
- the demo page now serves the built version of peaks
- enabled SourceMaps for an easier debug
Documentation
Merge pull request #50 from bbcrd/fix-builder

Peaks build system.