#4 Auto license

[Axel von Arnim]

There could be a new property in the .vai file, say
vainstall.license.type, that sets the name of a license
from within a group of predefined licenses:
GPL
BSD
QPL
...
Other

If the license specified is a known one (ie not
"Other"), it picks the corresponding license file and
all its available translations in the resource
directory and adds them to the package automatically.
If the user specified "Other", he is supposed to have
given a path to his license files, which are then added
to the package.

This feature spares time to the user who doesn't need
to get license files if he uses a VAInstall known
license. This guarantees also that the official texts
be used.