*: Fix up PORTREVISION

Mostly just typos and assigning PORTREVISION multiple times.

This commit doesn't fix up PORTREVISION between master-slave
ports where the master port often overwrites PORTREVISION from
the slaves which means the slaves don't actually get bumped.
These probably just need PORTREVISION?= but care must be taken
to not decrease the package versions of all the master-slave
packages and to actually bump PORTREVISION as intended. For the
record the currently visible broken master ports are:

databases/libgda5
emulators/virtualbox-ose
emulators/virtualbox-ose-legacy
graphics/atril
multimedia/mlt7
textproc/uim

But all master ports should be looked at here and get an explicit
PORTREVISION?= where it's currently missing to prevent this.

Reported by: portscan