Adds Galera server clustering mysql recipe

* Does a custom install of the MySQL-Galera multi-master
  cluster packages from Launchpad.
* Makes as few changes to the mysql::server and template
  files as possible, only adding required attributes to
  get Galera running
Missing closing parens for variable substitutions in my.cnf
Remove old init_node check and change support XA to 0 -- was a copy/paste error
Merge pull request #1 from jaypipes/galera

Adds Galera server clustering mysql recipe