java_gen: fix variable_name for classes
java_gen: add optional instrumentation
Makefile: remove all timestamps on clean
Merge into master from pull request #102:
Java gen: fix alignment for action set_field, add java_gen unit tests for actions (https://github.com/floodlight/loxigen/pull/102)
Merge branch 'master' of github.com:floodlight/loxigen