v0.4.1

Fix: file copying now works "cross device"

Installer

This now allows to duplicate the Python installation and installing more packages in one command like this:

output/bin/python -m ppd_instantiate foo requirements.txt
``

Launcher

Switch to a launcher approach because that enables dlopen(3) use.

Statically-linked

Turns out is is necessary to link Python statically, so we cannot just extract it from Alpine but have to build it from source. Special care is necessary to keep dlopen(3) working.

Alpine extract

Well, it works.