Add explicit dependencies for types

mysql_grant has an autorequire()'d dependency on the .my.cnf file used
by the provider to talk to the database.

I've added this to mysql_database and mysql_user too since logically
these also need the file to be in place.

I've hit this bug because of a slightly unusual edge case in our own
manifests, but I think this fix belongs upstream regardless.

lib/puppet/type/mysql_database.rb

@@ -3,6 +3,8 @@
 
   ensurable
 
+  autorequire(:file) { '/root/.my.cnf' }
+
   newparam(:name, :namevar => true) do
     desc 'The name of the MySQL database to manage.'
   end

lib/puppet/type/mysql_user.rb

@@ -4,6 +4,8 @@
 
   ensurable
 
+  autorequire(:file) { '/root/.my.cnf' }
+
   newparam(:name, :namevar => true) do
     desc "The name of the user. This uses the 'username@hostname' or username@hostname."
     validate do |value|