Synced in source from the mainline into siouxtool
to make it similar to the internal version.
Features added: New AppleEvent called "p4"
Previously, in your AppleScripts, you would say,
Now, you are also able to say,
They are identical and you are encouraged to discontinue
using "main" and use "p4" instead.
Syncing the source from the mainline also added in support
for the source to be built under Carbon.