implementation features better error reporting, and better compliance
with the PEP.

  something (overridable through Install-command entry)
- Hidden status is now determined by flavor == hidden, not by
  missing Download-URL. Hidden packages behave like installer packages.
- Made some error messages a bit more understandable.

Because there's new functionality the version has been upped to 0.5.

in no way affect library or include directories the code must take that into
account and not assume some options were found.

prevent leaving zombies.

(Removed at Ping's request.)

(Contributed by Jiwon Seo.)

LDFLAGS and CPPFLAGS for library and include directories, respectively.  Solves
issue of either env var containing other options that do not pertain to the
directories being searched for.

- using a different database for non-final releases should only be done
  for X.Y.0. Non-final micro releases can use the default database just fine,
  as they are required to be backward compatible.

the MACOSX_DEPLOYMENT_TARGET environment variable to 10.3 when calling the
loader. And we do this with "env" because distutils apparently doesn't
understand environment variable assignments before command names.

[Bug #1083110] calling .flush() on decompress objects causes a segfault due to an uninitialized pointer: fixes the problem and adds a test case