I'm looking into an issue with re-installing the VMConstruction module
after unloading (or rather uploading) it.  It appears that
"VMConstruction Plugins" has a cyclic dependency with "VMConstruction
Plugins Test".  There may be other examples in these two modules, but
here is one:

JPEGReadWriter2Plugin (in "VMConstruction Plugins") depends on the
definition of TestInterpreterPlugin (in "VMConstruction Plugins Test")

TestInterpreterPlug (in "VMConstruction Plugins Test") depends on the
definition of InterpreterPlugin (in "VMConstruction Plugins")

Now, of course, there is a good argument for re-organizing things to
eliminate this cyclic dependency.  But, setting that aside, should we
allow cyclic dependencies and handle that issue during activation by
first collecting all of the required modules, then installing the
collective items of all modules in an order that would not cause a
walkback?  Currently, the module system installs each module one at a
time, which makes it impossible to install two modules that are
co-dependent (without some trickery anyway).

- Stephen