Merge pull request #4 from mannol/#newircforfightingagainstkikels1488

It's not much but it's something #14/88
Big refactor: callbacks and related functions now take a Tox * instead of GC_Chat * && callbacks moved to group_handler
add group private messaging
add group peer ignore api function
Merge commit
ayy kekto
Current process, announcing should work but, untested. Test will be done once I watch a movie or something