apt: bundle apt.exe to allow update-in-place

[maphew]

for the apt package, make apt.exe the default instead of apt.py. Although this greatly increases the size of the download package it (should) allow updating everything in place, including python and apt itself.

[maphew]

Woohoo! apt-0.0-6.bz2 in the testing repository can successfully upgrade and replace earlier apt packages on at least one machine.

The ugly hack in r1179 is not worth it, and doesn't work anyway; need to parse the output of svnversion more intelligently (or ensure the build exe and pkg scripts are only run in a clean check out directory).

[maphew]

bundled apt.exe promoted to main repository as apt0.0-6.bz2