Revert geowiki separate class & backup changes

The whole "let's prepend $misc::statistics::geowiki::params::
everywhere" is super ugly & hard to read through. Case in point: this
broke puppet on stat1 with:

err: Could not retrieve catalog from remote server: Error 400 on SERVER:
Must pass directory to Git::Clone[geowiki-data-public] at
/etc/puppet/modules/git/manifests/clone.pp:34 on node
stat1.wikimedia.org

We could of course fix it in place, but the fact that it's so unreadable
makes it necessary enough to use a different approach.

This reverts commits ceb34961941e984c0646a761097da05430f1c6fd &
commit 0ec1823e5f9eccf62fd20fee424fb83bdbcfd155.

Change-Id: I7789080a16870ecd50e2a123f89f1ab8bd64e6de