Blender Git Loki

bugfix
the aspect of a block could become negative and default when scaling icons.
this is caused by the using viewRedrawForce (transforming a mesh) and drawing icons in the image panel.
must look into why bwin_getsinglematrix can give a negative value, probably because the opengl state is set incorrect.

This is still not correct because the aspect will be wrong. but at least it wont crash.