chore(grunt): adds grunt-ngdocs plugin

also integrates it into existing grunt configuration.
this is just the basic stuff, developer guide and tutorial
to come.
docs(ui.router.compat): adds docs for ui.router.compat module
docs(routerProvider): adds docs for routerProvider
docs(urlRouter): adds docs for urlRouter
docs(): wip docs for ui.router.state
Merge pull request #668 from PascalPrecht/ngdocs

ngdocs API documentation
docs(state): wip documentation for state service
fix(uiSrefActive): annotate controller injection

 - Fixes #671
docs(state): finishes documentation for state
docs(urlRouter): updates urlRouter docs

replaced the example with a much better one
also improves .sync() method docs
docs(resolve): makes resolve src ngdoc compatible
docs(stateDirectives): first draft docs for stateDirectives
docs(stateFilters): adds docs for state filters
docs($templateFactory): adds docs for $templateFactory
docs(view): adds docs for ui-view and $view
fix($state): allow null to be passed as 'params' param
Merge pull request #670 from PascalPrecht/ngdocs

docs(state): wip documentation for state service
feat(uiSref): add target attribute behaviour

Change the behaviour of ui-sref to match angular $location service,
ignoring any click event on an anchor with a 'target' attribute set.
Merge pull request #690 from roryf/ui-sref-target-fix

feat(uiSref): add target attribute behaviour
Merge pull request #684 from dlukez/state-null-fix

fix($state): allow null to be passed as 'params' param