* mpreal support
  to install mprf c++ bindings:
  - install mpfr (for example via apt-get install libmpfr-dev)
  - cd mpreal && sudo make install
** what works:
  - can be compiled using g++ 4.4.5
  - no memory leaks are present
  - test/storage works properly
** what does not work:
  - no unified printing interface for various data types including
    mpreal
** how did I solve it?
   - for mpreal replace all malloc, realloc and free with new and
     delete (this can be done using c++ specialized templates and
     existing ODE_MALLOC like macros).
   - replace memcpy with copying using '='