Added adapter class for increased pluggability. Added hook for 3rd
party invitation system to by pass e-mail verification
(`stash_email_verified`). Moved sending of mail to adapter.
Allow SocialApp to be used across multiple sites
added German translation
Merge pull request #143 from m-thielen/master

German translation
Fix typo in README in user_display section
Merge pull request #149 from tensafefrogs/master

Fix typo in README in user_display section
Prepping 0.8.3
merge 0.8.3