ACT-1698: Activiti fails to build when default charset is Windows-1252

Hi,
I encountered a minor issue when building activiti on my new windows box. This patch fixes it. I'll have a look and see if I can spot any similar issues using the String(byte[]) in the rest of the code base.
NB this issue affects both 5.12.1 and trunk but as it's pretty minor I'm not sure if it's worth fixing 5.12.*. I guess it depends how long you're planning to run with that branch.
Regards,
Rob