Dev/decode my302 (#254)

This PR adds support for decoding digital data from the my320 test chip.
- Added BitOffset (strong type)
- Expand 24 to 32 bit 
- Python bindings for decoding my302
- Improved docs

docs/src/python/file/pyTransform.rst

@@ -0,0 +1,27 @@
+Transform
+===================
+
+The transform module takes data read by :class:`aare.CtbRawFile` and decodes it
+to a useful image format. Depending on detector it supports both analog
+and digital samples. 
+
+For convenience the following transform objects are defined with a short name
+
+.. code:: python
+
+    moench05 = Moench05Transform()
+    moench05_1g = Moench05Transform1g()
+    moench05_old = Moench05TransformOld()
+    matterhorn02 = Matterhorn02Transform()
+    adc_sar_04_64to16 = AdcSar04Transform64to16()
+    adc_sar_05_64to16 = AdcSar05Transform64to16()
+
+.. py:currentmodule:: aare
+
+.. automodule:: aare.transform
+    :members:
+    :undoc-members:
+    :private-members:
+    :special-members: __call__
+    :show-inheritance:
+    :inherited-members: