Clean "TODO"s out of the code base!

[tngreene]

There are a bunch of TODOs in the code base saying things like "TODO: Is this needed"? "TODO: Remove me?" "TODO: [Something that got fixed]" and commented out code.

Not only is it sloppy, it is also confusing, to understand the state of the code. If there is a "TODO: Fix me" it should have a bug filed with it!

[tngreene]

xplane_bone.py:

• Sometimes uses a hard-coded 5

xplane_light.py

• Rounds axis_angle_theta in autodetection_algorithm to a hardcoded 5 digits

xplane_helpers.py

• in floatToStr, FLOAT_PRECISION = 8 is used to round numbers

Delete floatToStr because it is slow and terrible. See #347 for where it was fixed.

[tngreene]

• 4252dadf8 - xplane_config.debug/log removed
• 28fb74cde (and later b68193) - Remove XPLANE_OBJECT_TYPE_* constants
• Other dumb TODO comments removed in this time region

[tngreene]

c97a96411ee448cf1 - Renamed the terribly named "getWeight" method.

[tngreene]

Annoying uses of hasattr are not uncommon. For instance

                if hasattr(mesh, 'calc_normals_split'): # split normals
                    mesh.calc_normals_split()
                    supports_split_normals = True

                if hasattr(mesh, 'polygons'): # BMesh
                    mesh.update(calc_tessface = True)
                    mesh.calc_tessface()
                    mesh_faces = mesh.tessfaces
                else:
                    mesh_faces = mesh.faces

We're far in future already! Yes we have this stuff!