chore(grunt): adds grunt-conventional-changelog plugin

this plugin let's us autogenerate changelogs, all we have to do is to
follow the convetions this commit message follows

the angular.js project itself uses this convention too

we could then also somehow integrate the changelog task in one of the
release tasks
chore(package): fixing package.json structure

Per CommonJS Package specification (http://wiki.commonjs.org/wiki/Packages/1.0)
Merge branch 'grunt-conventional-changelog-support' of git://github.com/PascalPrecht/ui-router into PascalPrecht-grunt-conventional-changelog-support

Conflicts:
	Gruntfile.js
	package.json
release 0.2.5
feat(uiStateActive): directive to add/remove classes for active state

Adds a directive to switch a set of classes in a DRY fashion by interacting
with neighboring ui-sref directives.

The class to be used is an interpolated string, which is not $observed. There is
no default, as I do not wish to tie this module to a particular CSS model or
framework. A default may be configured in the future with a provider. As usual,
multiple classes may be used, as Attributes.$addClass/$removeClass will separate
classes on whitespace.

CAVEATS:

This is only capable of working as a parent of a ui-sref directive, or as a sibling
directive on the same element. In the future, there may be a mechanism around this,
but for the time being I can't think of what it would look like.

USAGE:

Sibling directive on same element as ui-sref:
<a ui-sref="foo.bar({baz: '123'})" ui-state-active="active" href>123</a>

--- OR ---

Ancestor directive of ui-sref:
<li class="item" ui-state-active="active">
  <a ui-sref="foo.bar({baz: '123'})" title="123" href>123</a>
</li>
chore(uiStateActive): refactor & add test coverage
Merge remote-tracking branch 'origin/caitp-issue-19' into issue-19-test

Conflicts:
	src/stateDirectives.js