implement apt-transport-mirror handling

[Artoria2e5]

close #88

[Artoria2e5]

Alright. It does work on my end now. The grep regex is quite complicated now, but well that's what it takes...

[Artoria2e5]

Got a seven-year-old bug fixed too.

[Lasall]

I tested the apt-transport-mirror with following configuration:

Sources list:

deb mirror+file:/etc/apt/mirrorlist unstable main non-free contrib
deb-src mirror+file:/etc/apt/mirrorlist unstable main non-free contrib
deb mirror+http://127.0.0.1/mirrorlist experimental main non-free contrib
deb-src mirror+http://localhost/mirrorlist experimental main non-free contrib

The local(host) mirrorlist(s):

http://deb.debian.org/debian/
http://ftp.de.debian.org/debian/

[Lasall]

I tested the shadowing with following test cases:

./apt-fast install "firefo*"  # should expand
_APTMGR="foo bar" ./apt-fast install firefox

[haidarns]

Hi, any update for this PR? or issue #88 ?