Add rewrites to vhost directories

(#MODULES-111) Duplicate rewrites parameter from apache::vhost
as an array of hashes placed in the directories parameter
to enable use of mod_rewrite directives in vhost directories.

Add documentation to Parameter directories for apache::vhost for
rewrites array.

Add tests to vhost directory rewrites

Add spec/acceptance and spec/defines tests for vhost entries of
directory with rewrites.

These tests are based on WP permalinks.
Merge branch 'ticket/modules-111-add_directory_rewrites' of https://github.com/blhughes/puppetlabs-apache into blhughes-ticket/modules-111-add_directory_rewrites

Conflicts:
	templates/vhost/_directories.erb
Merge pull request #811 from mhaskel/693-rebase

693 rebase