Switch /etc/my.cnf to /etc/mysql/my.cnf on 14.04

On Ubuntu 14.04 MySQL no longer looks for /etc/my.cnf before
/etc/mysql/my.cnf, this was causing MySQL to be launched with the wrong
configuration file. Moved bind address configuration into
/etc/mysql/conf.d/bind-inaddr-any.cnf and remaining replication related
configuration to /etc/mysql/conf.d/replication.cnf and eliminated
/etc/my.cnf on 14.04 hosts.

Leaving /etc/my.cnf on 12.04 hosts to reduce change on existing hosts.
Comment replication.cnf

Provide reason for apparently unrelated configuration items
Merge pull request #395 from blueboxgroup/fix-trusty-mysql

Switch /etc/my.cnf to /etc/mysql/my.cnf on 14.04
Fail run if nova user is already present with no homedir.
Add one-off playbook to give nova user a homedir.
Configure passwordless-SSH among compute nodes.

This is required for instance resize and migration.
Add support for defining /etc/network/interfaces.d files in host_vars
Updating CHANGELOG.md for 0.9.1 release
Merge remote-tracking branch 'upstream/master' into interfaces.d
testenv: bumping test instance boot delay
testenv: use nested KVM rather than QEMU
Merge remote-tracking branch 'upstream/master' into interfaces.d
Move verify-ssh to ~nova/bin/
Merge pull request #398 from blueboxgroup/testenv-use-kvm

testenv: use nested KVM rather than QEMU
Merge pull request #397 from blueboxgroup/interfaces.d

Add support for defining /etc/network/interfaces.d files in host_vars
Merge pull request #389 from blueboxgroup/migrate

Setup ssh keys for nova migrations
Create ~nova/bin
Merge remote-tracking branch 'upstream/master' into neutron-ml2