Attempt to detect without rebuilding that the "globally ignored" javatools -> xdk module dependency needs to be built

[lagergren]

If we change a line in the Javatools and rebuild the jar, this does not cause the xtc modules to be recompiled, which is preferred, since any Javatools change would really cause the every xtccompile and xtcrun task to rebuild, which is undesirable. This has to with the xdk depending on itself when it's being built. As there has been a complaint about the incremental build just running happily (supporting this case) but breaking since it doesn't know what to recompile. We should at least see if we can add a couple of lines of logic to warn that you need to do a full rebuild.