Set java file encoding on startup

Steps to reproduce:

On some platforms, e.g. Oracle JDK 1.8.0_92 on SLES 11SP4), Unicode in Opencast is broken unless the java system property

-Dfile.encoding=UTF-8

is set on the java command line on startup. As Opencast may be run in environments other than the officially supported OS/JDK combinations, we should set this in the opencast start script so it always works.

Actual Results:

When you create an episode or series with a unicode character in the title (e.g. Unicodé), it does not display correctly on the UI and is incorrect in some REST webservices, e.g. scheduler info to CAs.

Expected Results:

Unicode should work correctly in all aspects of Opencast operation.

Workaround (if any):