[pacman-dev] [PATCH] Add documentation for transaction events

[Sebastian Nowicki]

This is probably as good as it will get. I fixed the typos, and removed
the "No parameters..." lines. The enum documentation was wrong as well,
the brief actually added to the group's description, so I fixed that
too. The enum description now explicitely states that null parameters
are passed unless specified otherwise. Empty lines between comments were
removed to slim it down a bit, I don't think it really makes them any
harder to read.