Incorporating some changes after a review by Matt
I've put the initial version in the cache file back. I'm starting it
at version 1. Matt's version is 4, but there shouldn't be a confict
as the format of the version string is slightly different, his program
won't interpret this version/file as valid
Restored the initial age to 0 from 1. With the version in the file, I
no longer need to worry about reading old cache files from my earlier
versions of Jam
Tabified the file, so its a little closer to the Jam coding standards
A few tweaks, here and there