integrated new transforms module in the hexrd3 code base

extensions/README.md

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+Extensions source code
+======================
+
+This directory contains the source code for the different C extensions
+used by hexrd.
+
+The resulting code will appear as a python module under
+'hexrd.extensions', with a name
+
+Currently, the modules are:
+
+```_transforms_CAPI```: The original transforms CAPI, that will appear
+    as ```hexrd.extensions.transforms_CAPI``` in Python.
+
+```_transforms_CAPI_new```: Code reorganized in multiple files. Easier
+    to modify on a per-function basis. Will appear as
+    ```hexrd.extensions.transforms_CAPI_new``` in Python
+
+
+