refactor(sample): migrate sample app to 'best practice' directory layout

The current example is a bit too simplistic in my experience to fully grasp
the power of ui-router. It provides a monolithic example of state definition
that shows the varied approaches that can be used, but not in a very structured
format. This change applies the emerging best practice directory layout of an
angular application to exemplify the power of ui-router
Merge pull request #961 from mbroadst/improve-sample-structure

migrate sample app to a more 'best practice' directory layout
fix(state): allow view content loading broadcast
fix(uiSref): cancel transition if preventDefault() has been called
feat(uiSref): extend syntax for ui-sref

add possibility to pass params to current state without entering state name
Merge pull request #936 from fuzzlemuttons/patch-1

fix(state): allow view content loading broadcast
Merge pull request #966 from romario333/sref-preventdefault

fix(uiSref): cancel transition if preventDefault() has been called
Merge pull request #933 from timsly/current-ui-sref

feat(uiSref): extend syntax for ui-sref
feat($state): allow prevent syncUrl on failure

Check defaultPrevented before syncUrl on failure.
Merge pull request #967 from esion/sync_url_default_prevented

check defaultPrevented before sync url on failure
Automatically rewritten for npm.