Added volume command with optional +/- operators in sonoshell.py
commandline example.

This patch adds functionality for reading the current volume by running:
		python sonoshell.py <ip> volume

This patch adds functionality for adjusting the volume by running:
		python sonoshell.py <ip> volume +
or
		python sonoshell.py <ip> volume -
Added possibility for specifying jump factor.
 - Defaulting it the factor to 1 when volume + factor <0 or >100
Renamed variable for factor from x -> factor
Split out some spaghetti to two functions
 - adjust_volume
 - get_volume_adjustment_factor
Removed a redundant variable initialization.
Merge branch 'master' into cliVolume

Conflicts:
	examples/commandline/sonoshell.py
Simplified factor check, return False upon ValueError.
 - simplified operator checks to look at first index instead of .find
Simplified the factor check even more.
Make integration tests py.testable
Adding config files for pytesting
Using properties instead of methods
Minor fixes, default testing options
Merge pull request #62 from lawrenceakka/properties

Using properties instead of methods
Merge pull request #60 from lawrenceakka/pytest-more

Make integration tests py.testable
Merge pull request #45 from petteraas/cliVolume

Added volume command with optional +/- operators in sonoshell.py
Updated volume adjustment in examples/commandline/sonoshell.py
to use property volume instead of function volume()
Merge pull request #63 from petteraas/volume_properties

Updated volume adjustment in examples/commandline/sonoshell.py to use property volume instead of function volume()