Purge puppet created files on host when destroying

Cleanup files created by puppet in settings.d when `vagrant destroy` is
called. This will help ensure that subsequent `vagrant up` calls in the
same vagrant directory will trigger Exec['update database'] at the
appropriate time during the initial puppet run.

Note: this change modifies the mediawiki-vagrant plugin. The version
number has been bumped so that users will be prompted to update their
installed plugin version.

Bug: 62550
Change-Id: I677c3fc30646fa856ca22b5d67a96fc9757a27ec