Update changelog repository layout

[Lionel Le Folgoc]

13:11 jibel: mr_pouit, bug 45129
13:11 ubugtu-fr: Launchpad bug 45129 in update-manager "FFe: update-manager should have per-package changelog locations (was: uses changelogs.ubuntu.com for all packages)" [Wishlist,Fix released] https://launchpad.net/bugs/45129
[...]
13:24 wgrant: Old scheme is ARCHIVE_ROOT/changelogs/pool/main/f/foo-src/foo-src_1.0/changelog
13:24 wgrant: New is ARCHIVE_ROOT/pool/main/f/foo-src/foo-src_1.0.changelog
13:25 wgrant: With symlinks for each binary (foo-bin_1.0_i386.changelog etc.), pointing to the source changelog.
13:25 wgrant: So the changelogs are in the pool with the rest of the files, not a strange separate one.

So we need to:
- duplicate medibuntu/conf/changelogs.sh for lucid, with the new path (CHANGELOGDIR=./)
- create a new hook that adds the symlink when a binary package is uploaded

Reprepro script ref (as a reminder, $* == unknown number, see medibuntu/conf/changelogs.sh):
$1: action (add|remove|replace)
$2: codename
$3 package type
$4: component
$5: architecture
$6: package name
$7: version added (for add), version removed (for remove)
$*: --
$*: file key of the added/removed file

for replace:
$7: version added
$8: version replaced
$*: --
$*: file key of the added file
$*: --
$*: file key of the removed file

[Lionel Le Folgoc (mrpouit)]

The only missing info is the source name, we can probably obtain it with:
dpkg -f "file key" Source
or dpkg -f "file key" Package if the former is empty.