batmand: Use git repository to retrieve sources

batmand: Use git repository to retrieve sources

The current package is build around the subversion repository which does
not exist anymore. The package can therefore be moved to the git repository
to have an official source for the revision used in OpenWrt.

The SVN version of batman r1439 was actually r1435. The git export of revision
r1435 is referenced by this commit. The version number was only increased
to 1440 to create a new source tarball. SVN revision r1440 is not a commit
for batman and therefore no code changes in batman was done in r1440.

Signed-off-by: Sven Eckelmann <sven@narfation.org>