bugfix and flip feature

fix the transformation bug in gr3_surface
use OPTION_FLIP from gr_setscale in gr3_createsurfacemesh

Change-Id: Icd6835652d0a65f4aece3dfd72ca1a12f003a978
Reviewed-on: https://iffwww.iff.kfa-juelich.de/review/12
Reviewed-by: Fabian Beule <f.beule@fz-juelich.de>
Reviewed-by: Josef Heinen <j.heinen@fz-juelich.de>
Added GR3 accelerated Mandelbrot example

Change-Id: I9ac42b1645213686cd2df954849addfa06c4c716
Reviewed-on: https://iffwww.iff.kfa-juelich.de/review/13
Reviewed-by: Josef Heinen <j.heinen@fz-juelich.de>