Stubs of the functions allowing the upper JAVA layer (user interface) to get back...

Stubs of the functions allowing the upper JAVA layer (user interface) to get back some information from the bottom one (context implementation). These are only stubs here because this file is not involved in libsimgrid4java; xbt_jcontext is used instead, but I'd prefer to wait before commiting this one

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/simgrid/simgrid/trunk@3671 48e7efb5-ca39-0410-a469-dd3cf9ba447f