Mavenize SPIMAcquisition plugin

Moved the source files into src/main/java, added pom.xml, revised
build.xml for Ant builds to still work.

Signed-off-by: Luke Stuyvenberg <stuyvenberg@wisc.edu>
Disabled metastage for initial MM submission

We're getting ready to submit PicardStage to the MM team, and I don't want
the metastage code having any effect right now, until I've had more time
to bug-test it.

Signed-off-by: Luke Stuyvenberg <stuyvenberg@wisc.edu>