port e3e30ff94964fddd5764fd64391dcf8216354264 from Pd-l2ork: forgot to convert configure.in to configure.ac

*removed qt from autobuilds since qt5 is not standard in Ubuntu 12.04 and besides we need to update control files as well as online documentation

*improved installer to make it easier to recompile pd-l2ork when continuing development after building a snapshot deb or tarball installer (the pd folder will retain config script with the appropriate --prefix flag)