feat(newpage): Changed the provider and pagerequesthandler

- githhubcontentprovider has a new function to create a new page
- the pagerequesthandler will detect automatically if a page does not
  exists and will call the createpage in this case
feat(newpage): Added feature to create new page

- New Dialog to enter the name of the new page
- PagesCtrl sets now the pages also to the $rootScope
- EditContentCtrl has a new function to create a new page
feat(newpage): Renamed pageService.updatePage

closes #63
I've updated the name of this function to *savePage* because
it will also be called from *createPage*