Added CTM converter.

Command line Windows executable from OpenCTM install.

utils/exporters/ctm/LICENSE.txt

+Copyright (c) 2009-2010 Marcus Geelnard
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must not
+    claim that you wrote the original software. If you use this software
+    in a product, an acknowledgment in the product documentation would be
+    appreciated but is not required.
+
+    2. Altered source versions must be plainly marked as such, and must not
+    be misrepresented as being the original software.
+
+    3. This notice may not be removed or altered from any source
+    distribution.