New property interface
We want to replace property handles with string ids. The new interface should look like this:
single-item access:
val = mesh.vertex_property('test_prop', vh) mesh.set_vertex_property('test_prop', vh, val)
all-element access (generic):
list = mesh.vertex_property('test_prop') mesh.set_vertex_property('test_prop', list)
all-element access (numpy):
arr = mesh.vertex_property_array('test_prop') mesh.set_vertex_property_array('test_prop', vh, arr)