Change support library and compile sdk to 21
Add files ElementPagerActivity.java and activity_element_pager.xml
Add ElementPagerActivity.java, previous commit didn't add anything, sorry for that.

activity_element_fragment.xml wasn't needed.
Add file ids.xml to asign id to viewPager
Add PagerAdapter to viewPager
Rename file ElementInfoActivity.java to ElementListFragment.java
Turn activity listing all the elements in a fragment

delete file activity_element_info.xml
delete file acivity_element_info.xml
Improve constructor of ElementListAdapter class
Fix error with wrong parameters for onCreate in ElementPagerActivity.java
Add action bar item to ElementPagerActivity
Add onOptionsItemSelected() to ElementPagerActivity

And show element list button from menu directly on action bar