add mysql::perl

An additional helper class to ensure that the Perl MySQL DBD driver is
installed (DBD::mysql).
mysql::perl tests
...and add mysql::perl to README.md
...and credit $self, too.

Why not?
A very small fix for the case where the root password has been changed
by hand and then you change your mysql::server entry to match.  If you
also change any mysql::db entries at the same time this causes those to
be attempted before your /root/.my.cnf is updated.

I can't add rspec testing for this until https://github.com/rodjek/rspec-puppet/pull/106
is merged.
Merge branch 'master' into topic/perl

Conflicts:
	manifests/init.pp
add a maximum connection parameter and set the default to 1000

Conflicts:
	manifests/config.pp
	templates/my.cnf.erb
changed the test accordingly to the new max-connections parameter

Conflicts:
	spec/classes/mysql_config_spec.rb
changed the max_connections default to 151

this is the default according to the mysql manual.
https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_max_connections
Merge pull request #186 from apenney/rootpassword

(WIP) #20562: Minor fix for ordering
Merge pull request #187 from RsrchBoy/topic/perl

add mysql::perl helper class
Merge branch 'master' of https://github.com/puppetlabs/puppetlabs-mysql
Merge pull request #198 from mhellmic/maxconnections

add a maximum connection parameter and set the default to 1000
Merge branch 'master' of https://github.com/puppetlabs/puppetlabs-mysql

Conflicts:
	manifests/config.pp
	spec/classes/mysql_config_spec.rb