amipkg 0.5.2

Tidy installs: a recipe-less package now lands in its own drawer unless the archive brings exactly one top-level drawer of its own - loose files no longer pile up in the install directory root (tester report: flat archives like amipkg-client and Amelinium spilled their files there). Same rule in the on-Amiga client (all front-ends) and Amiga Imager's Manage Amiga Software. Upgrading an affected package cleans up the old loose files automatically (receipt-driven remove runs first).