Test for default parameter 'mandatory' value
Added tests for more dynamic parameter set selction based on pipeline value
Fixed tests to work with PS
Improved parameter binding

It's now more careful with pipeline-related decisions.
- In the early (command line parameter) binding stage, the user will
  only be already asked for missing parameters if there is no parameter
  set that might be completed by pipeline
- Binding pipeline parameters won't try it first with the default set,
  as this lead to the preference of data-type conversion over usage of
  the unconverted pipeline parameter in other set
More elaborate parameter set selection
Refactored parameter bidning to reduce complexity
Merge pull request #299 from sburnicki/mand_tests

Improved cmdlet parameter binding