No longer using a separate include file for the Wix sources - too confusing.
Closer to generating an MSI, but still not working.  This has two outstanding problems: the first having to do with the WXS file generated by heat, and the other being that major and minor version numbers greater than 255 aren't supported (a Windows Installer limitation, not WiX's problem.)  To work around the version number problem, I've truncated "2014.1.0" to "14.1.0".  I need to look at how NSIS records the version number in Add/Remove Programs.  It ought to have a similar problem.  I'm assuming that it automatically munges the version number to make it work.