Squid-3 style

Update on the Squid-3 source style guidelines.

Robert has now disabled the astyle checks on committed code. astyle
isn't really up to the job quite yet. Instead we will have to do manual
styling for now.

It also means that it's OK to fix some of the really stupid things
astyle has done to the code.

General style guidelines is still in principle what astyle does, minus
where it's plain stupid.

Regards
Henrik