Patch for Ranges

Hey All -

I've been testing range requests in Squid-3 inpreparation for trying to
change it to cache partial objects. In the process I've discovered some
bugs. I've posted these via Bugzilla (bugs 628, 632, 636, 639, 645, 646,
647 and 650) and I thought I'd also try to send out a patch of my changes
here. Also, these changes are meant to be applied after a source download
has been built (I haven't really gotten into how creating a build works).

With this set of changes, I've also included code to change the way
range_offset_limit is specified, adding the keyword 'none' to imply a -1
value and eliminating all other negative values. This code is pretty
redundant though (I just replicated the parsing functionality and changed
it for the range_offset_limit variable only), as I didn't want to step on
any other parsing functionality. I've included a change to squid.conf too.

Also, I'm a little worried about the bugs I posted on Bugzilla, since
there's no place to specify in the form that they're for version 3.0.
They're in there now, though, so hopefully it's ok that I put them there.
If I need to I can go back and change them (hopefully).

Finally, my next step is to try to get partial object caching working, so
if anyone has any notes, ideas or (pseudo)code out there please let me
know.

Thanks,
Leeann