components: rename tarball to match Debian expectation

Horde_HashTable-1.0.0beta2.tgz -> php-horde-hashtable_1.0.0~beta2.orig.tar.gz
Horde_Pear: Ignore comments in package.xml, as found in Horde_Kolab_Filter

See http://bugs.horde.org/ticket/11938
Debian: Adapt Debian template for team packaging