CodeCoverage of files containing DSC Configurations

DSC's use of dynamic keywords screws with the code coverage breakpoint-based implementation quite a bit.
This commit gets it working, more or less, by ignoring commands in the file which do not trigger breakpoints even when they're executed (based on trial and error.)
Small update

Revised new code slightly so most of it is only executed on PowerShell v4+.  Dynamic keywords didn't exist in v3.0, and executing IsChildOfHashtableDynamicKeyword might have caused errors when StrictMode is enabled.
Merge pull request #163 from dlwyatt/CoverageOfConfiguration

CodeCoverage of files containing DSC Configurations