Also plumb in script library to build scripts, and replace a bunch
of shell script with LiveCode.

In particular, move the packaging code from
revIDEDeveloperExtensionLibrary, so that we specify exactly what files
are put in the package rather than recursively zipping the extension
folder

There's not really an ideal place for something like a server
script that provides access to an extension, so move it to resources
folder for now.