BK snapshot process updated

Well, by updated, I mean fixed. :)

For 2.4, nightly BK snapshots are being generated once again at
http://www.kernel.org/pub/linux/kernel/v2.4/snapshots/

For 2.6, I fixed a bug that caused the script to break whenever the version number format changes (even from 2.6.8-rc1 to 2.6.8 required manual invention). Nightly BK snapshots are being generated at the familiar location,
http://www.kernel.org/pub/linux/kernel/v2.6/snapshots/

The snapshot version is always $kversion-bk$snapshot

Jeff