Hopefully this helps with issue 320

Cleaned up the code

Made some progress with the helpfull comments of Sean and Rob.

The last change is somewhat iffy. I've created the custom object but do you want it to write to the host or do you want to write it to a file?

Fixed a little bug with a wrong column name in the output.

Excluded the finally from the try catch. It got there every time for no apparent reason.

Assert-DBGrowthEvent added to the InstanceAssertions.
Removed the commandline output in the GetDatabaseDiskFreeSpace that has been replaced with the custom function.