Blender Git Loki

Fixed bug in convert function with Mesh objects.
Objects with no modifier could still be converted, but resulting meshes were corrupt and segfaulted Blender when cycling edit mode.
This tests each mesh object for modifiers before converting.

Resulting metaballs meshes were not visible in wireframe.

Also made the selection context nicer, All new converted objects are selected while objects that are converted are deselected.