Version and/or date compiled

A few systems I have been using show the version of the software as the first line in the response to running the program. Others have a command option "-version" to get the software version. It would be nice in development if we had a way of checking the version/date of the compilation for confirming what is actually running.

For VXQuery we could implement this as a built-in function that returns an either a string or an element with this information. This way, there version information for the server would be available to all clients.