#288 Add support for source devpaks

[Michal Molhanec]

It would be nice if packman have support for source
devpak. E.g. the devpak will contain sources and a
makefile. The packman will unpack it to some temporary
place, run make and then copy the created files to the
right place (using .DevPackage as always).

This will resolve the problem that C++ ABI is different
between different versions of GCC.