[packagekit] transaction errors from the yum backend

[Matthias Clasen]

";".join(msgs.value) gives the expected result:

error	transaction-error	Error in Transaction Processing;ERROR with
rpm_check_debug vs depsolve:;Package otherapp conflicts with
someapp.;Please report this error in bugzilla

But looking at the text, I somewhat doubt that yum will give us error
messages of sufficient quality.