Update Gather.pm

First part for issue #135: optimize the calls made, and add a optional argument to the is_redhat, is_alt, ... calls. They will get an argument when being called inside Service.pm -> get(), so as to avoid multiple calls to get_operating_system()
Update Service.pm

Second part for issue #135
added equery for Rex::Pkg::Gentoo in get_installed

Since epm is hardmasked, it's not very likely that most Gentoo users will have it installed.

equery comes from gentoolkit, and is much more likely to be installed, and can generate equivalent output to epm -qa very easily, so I've added a can_run('equery') check to get_installed to toggle behavior.
updated most of Rsync with server-specific auth

As it was, the Rsync module/command was taking most of its config directly from Rex::Config, when get_current_connection->{server} is a Rex::Group::Entry::Server that has proxy methods for most of what it was using, so now it supports group-specific/server-specific auth for the most part.
fixed df and mount issue
updated buildfiles
updated manifest
Update Gather.pm

RedHatEnterpriseES also a clone of RedHat
removed blastwave #146
added option to run sudo with different user on the fly - #128
Merge remote-tracking branch 'liedekef/patch-6' into 0.42
Merge remote-tracking branch 'liedekef/patch-7' into 0.42
Merge remote-tracking branch 'liedekef/patch-3' into 0.42
Merge remote-tracking branch 'tianon/patch-1' into 0.42
Merge remote-tracking branch 'tianon/patch-2' into 0.42
Merge branch '0.42' into feature/net-ssh-any