Don't hardcode JAVA_HOME
Don't hardcode JAVA_HOME

The default JAVA_HOME directory may not exist, but the makefile will
still work when invoked with JAVA_HOME=FOO make.

meraki/scalaqlite,ongmingyang/scalaqlite,ongmingyang/scalaqlite,meraki/scalaqlite,ongmingyang/scalaqlite,meraki/scalaqlite