Created file for lvm state. Implmenetd vg related functions
Added functions to create/remove logical volumes ref #118
Added function for creating pysical volumes. ref #118
Added comments to functions. ref #118
Fixed calls to lvdisplay salt command.
Added module comment block
Caught error cases in display commands for lvm module.
Use kwarg for lvm absent
Added docs for lvm state
Added docs for lvm state
Use return codes from lvm commands.

This prevents some stack traces from attempting to process
invalid output from lvm commands.
Typo fix
Merge pull request #4715 from shadowfax-chc/lvm

Lvm State