Enable concurrent installs of runtime packages after a soname change.

Enable concurrent installs of runtime packages after a soname change.
Add a common package for afm metrics, and other 'static' data and utilities.
Remove the version/flavour from afm installs on unix as discussed with Vaclav,
these files really do never change.
Mention --static along with other selection options in --help.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@29492 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775