Windows install to custom location after building from source

["Martin v. Löwis"]

>> Just create an empty one.
> 
> Won't quite work: merge tries to find full_current_version
> which is determined (if None) in msi.py from the rather
> involved current version stuff.

Only if you don't pass an msi file on the command line. So
I recommend that you do that.

> I'm going to give up on this for tonight, but one possibility
> is to turn msi.py into an importable module and for msilib
> to import it and pull the config values from there.

Please, no. The only way I could accept that if merge.py would
be run at the end of msi.py (i.e. merge.py disappears).

Regards,
Martin