TEST: Parameter aliases and prefixes

Adds tests for:

1. Parameter prefixes: Get-Variable -Nam a
2. Parameter aliases: Get-Process -ProcessName mono
3. Parameter aliases by prefix: Get-Process -ProcessN mono
4. Passing a named parameter with no mathc produces and excpetion:
Get-Process -Procecc mono
TODO: Document outstanding logic changes for parameters
Invalid parameters should cause exception

This now fails with exception as Procecc is not a valid
parameter for the Get-Process Cmdlet:

	PASH /> Get-Process -Procecc mono
Allow parameter aliases and prefixes

Allow parameters to be specified by only specifying
part of the parameter name (although in powershell this
is widely considered poor practice).  Enough of the
parameter name must be specified to avoid ambiguity with
other parameters.

This also adds support for specifying parameters by their alias
and also allows specifying them by prefix as above.

As a result these styles of parameter passing now work:

	PASH /> Get-Variable -Nam a
	PASH /> Get-Process -ProcessName mono
	PASH /> Get-Process -ProcessN mono
TEST: cleanup and enable passing tests
Merge pull request #109 from b333z/paramchanges4

Allow named parameters to be specified by alias and prefix