Remove unused trove dependency

This is a reminder because I keep forgetting this:

The trove dependency (net.sf.trove4j:trove4j:jar:3.0.2:compile) was introduced because of a hack work-around for hib3/JPA1 && hib4/JPA2 compatibility.

It turned out the work-around wasn't necessary – but although the code for the work-around has been removed (ByteArrayBlob thingy-class), this dependency has not been removed.

There are also some lines in the pom.xml (with regards to modifying code under the hibernate-4 profile) that can should also be removed.