Follow the SNAPSHOT version of mpicbg.jar

This also helps MiniMaven in the Fiji project which would otherwise
confuse 20111128 (the version inferred from the Scijava POM) to be a
higher version number than 0.6.0-SNAPSHOT and prefer the older version.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge pull request #11 from imagej/mpicbg-version

Follow the SNAPSHOT version of mpicbg.jar