added full path to config file ignored_environments.yml
fixed typos from previous commit
Merge pull request #279 from Riptawr/gh-pages

added full path to config file ignored_environments.yml, fixed typo
Email Configuration section added

Content pulled from http://projects.theforeman.org/projects/foreman/wiki/Email_configuration and entered in with proper formatting.
Merge pull request #280 from ntent-ashton/patch-1

Email Settings Documentation
Fixed formatting mistake

I used the wrong version of MarkDown, broke the live manual's formatting.
Merge pull request #281 from ntent-ashton/patch-1

Fixed formatting mistake
Documentation: Fix small type DHS -> DNS
Merge pull request #282 from Spredzy/fix_typo

Documentation: Fix small type DHS -> DNS
Per-OS installation instructions

Fixes various things like CentOS 7 SCL instructions, per-Debian/Ubuntu release
sources, more detailed instructions for RHEL channels and explicit Puppet Labs
repo instructions.