Fix issue with bash binary location in FreeBSD

special case for root user

modified visudo to only report change in salt when there is an error. also add option to remove keys from ssh_auth

Only include users.sudo when a user with sudouser is declared.

Support Gentoo minions

Add support FreeBSD using map.jinja (Tested on Freebsd10)

Specify bash shell when validating sudo snippet

Since we are using bash specific features and sometimes you can end up getting /bin/sh - see https://github.com/saltstack-formulas/users-formula/pull/30#issuecomment-44224106

Overwrite a sudoer file rather than append to fix #21

Do not echo Public/Private keys to stdout when running the state

Ensure that we are sudo includes /etc/sudoers.d

It doesn't by default everywhere - without this the sudo_rules option won't work

Validate user sudo rules before applying them

Add Password if the state supports it.

corrected url for formulaes...

New format of handling user.absent, supporting additional parameters

Fix incorrect sudo_rules example

Add home to pillar.example

Fix pubkey privkey typo

Fixes #22

Add absent_groups pillar to remove groups.

Updated structure of readme, bumped License to 2014.

Check for sudo_rules before text.append state.

Since ebe5198f, if a user's pillar dict didn't contain sudo_rules, a broken
file.append state would be rendered (since some text is required). With
this patch, the file is still created/managed by the previous state, but
will be empty by default if created fresh. This seems a more sensible
default than assuming a default sudoer policy.

Further, since the first word on each rule line should be the user's
name, that is now assumed.

Changed 'contents' to 'contents_pillar' to correctly parse newlines for private/public SSH keys.

Fix ssh_auth.names in example pillar

Change .ssh directory permissions to 700