[COOK-4373] Add conditional output of optional attribute for cache_peer to template

Signed-off-by: Sean OMeara <someara@opscode.com>
[COOK-4376] remove duplicated attributes

Signed-off-by: Sean OMeara <someara@opscode.com>
[COOK-4377] Generate a sysconfig on Fedora as well

Signed-off-by: Sean OMeara <someara@opscode.com>
Version bump to 0.4.0
Publish 0.4.0 Changelog
Version bump to 0.4.1 (for development)
[COOK-4320] - Add support for ubuntu 13 to the squid cookbook

Signed-off-by: Sean OMeara <someara@opscode.com>
Version bump to 0.4.2
Publish 0.4.2 Changelog
Version bump to 0.4.3 (for development)