Blender Git Loki

===Tools===
Previous patch for "problems with STL iterators/vectors that only show up under
Visual Studio 2005" could cause a crash when object used as a boolean modifier
was changed (for example, flipping all the normals). The problem is that result
of boolean operations (apparently) can result in empty meshes. Patched to
use the vector::size operator to check for empty vectors before trying to
check the iterator.