[MainActivity] added menu to tell a friend about simlar

  * This fixes issue #98.
[resources] updated german translation
[AgreeActivity] now uses https links
[ContactsProvider] now has fake data mode
[ContactsProvider] added fake phonebook picture
[MainActivity] added menu entry for fake telephone book data if version has debug tag
[MainActivity] Code Cleanup: coding style
Merge pull request #139 from simlar/tell-a-friend-and-fake-telephone-book-pullrequest

Tell a friend and fake telephone book pullrequest