Get java binding available to other java binding

This is a tricky point of SWIG.
The case is when we want to use the java binding of AvTranscoder into an other java binding of an other application, and inherited from a class of AvTranscoder.
To do this, SWIG needs to use functions to cast object to an other and make the hierarchy of java classes works. The problem is that these functions are internal, and can't be accessible by the java binding of the other application. The pull request makes these functions public.
Here more information about this issue: http://sourceforge.net/p/swig/mailman/swig-
devel/thread/4ED006FD.6020403@fultondesigns.co.uk/

Also rename dynamic libraries on windows (<name>'-'<version>.dll).