Build script enhancements

While working on another feature branch, in which a new project was being added to the solution, it became clear that there were multiple things a developer had to remember to get right:

1. You had to remember to set the Build Output path to ../../Build for both Debug and Release mode, when the project is meant to be deployed.
2. You had to remember to update the copyright date span in the LICENSE.txt file each year even though AssemblyInfo was correctly updated automatically.
3. You had to remember to shorten the default AssemblyInfo.cs file and manually include the generated CommonAssemblyInfo.cs file.

This branch addresses all of these concerns.  Build output paths are sanity checked so that when a new developer attempts to add a project, they'll be reminded to take part in the special build folder.  LICENSE.txt's copyright date span is updated just like it is for AssemblyInfo.cs files.  AssemblyInfo.cs files are overwritten in their default location, so that you no longer have to manually add a link to CommonAssemblyInfo.cs.