Build: Manage dependencies with bower

Fixes gh-6369
Added jquery.ui.tabs.js
Use gseguin's  fork of grunt-bowercopy until fix lands
When timmywil/grunt-bowercopy#5 lands we can resume to use the released version
Added jquery.ui.tabs
Split jquery, jquery-ui & jquery-plugins into separate bower copy targets
Process jquery-ui files to replace `@VERSION` token by commit hash
Processed content
Replaced `@VERSION` token by the commit hash
Re-added jquery.ui.tabs for real this time
Had to create a separate bowercopy target as it's using a different revision than the other UI components. Will align them in a separate PR.
Use not yet released grunt-bowercopy version
grunt-bowercopy 0.5.0 was released, yay! Use it
Addressed code style issues