add a simple webserver for our testcases

add a simple webserver for our testcases

APT needs to acquire data in a secure fashion over an inherently
unsecure way, known as the internet, while communicating with
unreliable partners, known as webservers and proxies.

For your integration tests we so far relied on 'normal' webservers,
but all of them have certain quirks and none is able to provide us
with all quirks which can be observed in the wild and we therefore
have to test with, so this webserver isn't trying to be fast, secure
or feature complete, but to provide all the quirks we need in a
consistent way.

This webserver also makes the APT project self-contained, as it is now
able to generate, serve as well as acquire package indexes. ;)

Git-Dch: Ignore