[#57/#88] added HockeyApp SDK (2.0)
[#57/#88] catch exceptions and send manually

we don't want to crash the whole app after every exception, but if we
don't crash it, then we need to hack HockeyApp a bit because it doesn't
really support sending exceptions in any other way than through a crash…
[#57/#88] added self-signed cert for keychain

otherwise you get an annoying popup when trying to access the keychain
fixed missing transactions issue again

I think this was the original reason, not using the XML store - the
transactions were only saved in a child context but not in the parent
context which actually writes them to disk
added core data transaction list to debugging info