Windows Templates and Pipeline Fixes

This PR starts to integrate the new content pipeline with the Windows VS templates.

 - Fixed up the templates to appear in VS with some reasonable order. (Fixes #3191)
 - Removed old .targets file and fixed up the new one.
 - Removed old Content VS template project.
 - Added support for new content pipeline to Windows template.
 - MGCB no longer shows usage on empty content builds.
 - Fixed Pipeline tool to use EXE path for loading item templates.
 - Fixed build script to delete old template .zip files before rebuilding them.

Yea...  the VS IDE tries to be smart and detect that no rebuild is needed by looking at the source files.  Of course it has no clue that the `.mgcb` file links to other files that could be changed.  So it will happily skip building even when there are changed content files.

`<DisableFastUpToDateCheck>` is also used in Microsoft XNA's .targets for the same reason.