176 bugfix contrib matlab 2013a

summary:

v2012b:
* pull out Java as dependency; MATLAB's JRE appears more robust solution
* employ preinstallopts/installopts construct
* quadraple heap: `_JAVA_OPTIONS="-Xmx512m"`; important to prevent subtle failures
* add `toolbox/local/classpath.txt` to fail-hard, when build is not finishing properly
* modextravars defines `_JAVA_OPTIONS`

v2013a:
* all of v2012b conveniences, as described above
* use 7z to extract directly from the .iso, no man-in-the-middle needed any more
* added hpcbios banner, since this implements the solution for climate scientists' needs