Added state for layman.

Adds the ability to ensure overlays are added or deleted via layman
Console logger now writes to `sys.stderr`. Make PyLint happier. Fixes #3135.
Chaned layman state functions to conform to other states.

Changed added to present and deleted to absent
Added virtual to layman state
Add some more documentation to the `BufferedReader`. Refs #3127.
Minor doc indentation fix.
Added code for test interface to layman state
Added docs for layman state
Replace succesful with successful (reported by lintian)
Fix mdadm module: do not return False on Linux kernel
Add the ability to modify or create repos
Merge pull request #3144 from havan/fix-mdadm-module

Fix mdadm module: do not return False on Linux kernel
Merge pull request #3145 from techhat/repo

Add the ability to modify or create repos
Merge pull request #3141 from s0undt3ch/issues/3135

Console logger now writes to `sys.stderr`. Make PyLint happier. Fixes #3135
Merge pull request #3142 from s0undt3ch/develop

Add some more documentation to the `BufferedReader`. Refs #3127.
Merge pull request #3140 from shadowfax-chc/layman-state

Added state for layman.
finish up layman state test interface
Merge pull request #3143 from mrud/mru/spelling

Replace succesful with successful (reported by lintian)
Redirect warnings to the logging system on python versions >= 2.6  Refs #3135.
Typo.