Fix for EZP-20930: missing REST root resources

http://jira.ez.no/browse/EZP-20930

Adds the missing URLs to the REST root resource.

Adds a dependency on https://github.com/hautelook/TemplatedUriBundle that allows us to generate RFC-6570 compliant URIs through a custom router. 

## Added resources:

### Root
- `/Root/contentByRemoteId`
- `/Root/contentTypeByIdentifier`
- `/Root/contentTypeGroups`
- `/Root/rootUserGroup`
- `/Root/locationByRemoteId`,
- `/Root/locationByPath`
- `/Root/objectStateGroups`
- `/Root/objectStates`
- `/Root/globalUrlAliases`
- `/Root/createSession`

### Other

#### ObjectStateGroup

- `/ObjectStateGroup/ObjectStates`

#### Content

- `/Content/ObjectStates`

#### Location

- `/Location/UrlAliases`

#### ContentType 

- ` /ContentType/Draft`
- ` /ContentType/Groups`

#### User

- `/User/Groups`

## Example output
```xml
<Root media-type="application/vnd.ez.api.Root+xml">
 <contentByRemoteId media-type="" href="/api/ezp/v2/content/objects?{&amp;remoteId}"/>
 <contentTypes media-type="application/vnd.ez.api.ContentTypeInfoList+xml" href="/api/ezp/v2/content/types"/>
 <contentTypeByIdentifier media-type="" href="/api/ezp/v2/content/types?{&amp;identifier}"/>
 <contentTypeGroups media-type="application/vnd.ez.api.ContentTypeGroupList+xml" href="/api/ezp/v2/content/typegroups"/>
 <users media-type="application/vnd.ez.api.UserRefList+xml" href="/api/ezp/v2/user/users"/>
 <roles media-type="application/vnd.ez.api.RoleList+xml" href="/api/ezp/v2/user/roles"/>
 <rootLocation media-type="application/vnd.ez.api.Location+xml" href="/api/ezp/v2/content/locations/1/2"/>
 <rootUserGroup media-type="application/vnd.ez.api.UserGroup+xml" href="/api/ezp/v2/user/groups/1/5"/>
 <rootMediaFolder media-type="application/vnd.ez.api.Location+xml" href="/api/ezp/v2/content/locations/1/43"/>
 <locationByRemoteId media-type="" href="/api/ezp/v2/content/locations?{&amp;remoteId}"/>
 <locationByPath media-type="" href="/api/ezp/v2/content/locations?{&amp;locationPath}"/>
 <trash media-type="application/vnd.ez.api.Trash+xml" href="/api/ezp/v2/content/trash"/>
 <sections media-type="application/vnd.ez.api.SectionList+xml" href="/api/ezp/v2/content/sections"/>
 <views media-type="application/vnd.ez.api.RefList+xml" href="/api/ezp/v2/content/views"/>
 <objectStateGroups media-type="application/vnd.ez.api.ObjectStateGroupList+xml" href="/api/ezp/v2/content/objectstategroups"/>
 <objectStates media-type="application/vnd.ez.api.ObjectStateList+xml" href="/api/ezp/v2/content/objectstategroups/{objectStateGroupId}/objectstates"/>
 <globalUrlAliases media-type="application/vnd.ez.api.UrlAliasRefList+xml" href="/api/ezp/v2/content/urlaliases"/>
 <urlWildcards media-type="application/vnd.ez.api.UrlWildcardList+xml" href="/api/ezp/v2/content/urlwildcards"/>
 <createSession media-type="application/vnd.ez.api.UserSession+xml" href="/api/ezp/v2/user/sessions"/>
</Root>
```

## Related pull request
- https://github.com/ezsystems/ezpublish-community/pull/70

## TODO
- [x] Tests (really not a big fan of visitor tests, but well...