Dev ops guys updates

These are the tooling updates that I've been working on within DevOpsGuys over the past couple of months.  The DscConfiguration module has the most extensive changes, and many of the design decisions there were made in collaboration with Steve.

There's still more work to be done before this branch is ready to be merged into master; I just wanted to get this code out into the public repo asap.

The motivation behind these changes was to get the tooling modules to a point where we can train clients to use them in a continuous delivery pipeline.  The biggest priorities were creating examples of the folder structures required by DscConfiguration and DscBuild, and simplifying the Resolve-DscConfigurationProperty API and code.  We've also tried to improve the overall user experience by making minor changes in other places; making Invoke-DscBuild run faster, making failed Pester tests or failed calls to Test-cDscResource abort the build, making Test-cDscResource stop reporting failures for resource modules that are actually valid, etc.