Added README.md

README.md

+# SWIG wrappers for the Community Sensor Model
+
+This repository contains SWIG wrappers for the CSM. The wrappers are currently
+only be created for Python, though many other languages can be supported.
+
+## Building & Installing
+- Ensure that the library is installed
+- (Optional) Install the USGS CSM_CameraModel libraries to ensure that this
+  wrapper is able to do something.
+- mkdir build
+- cd build
+- cmake .. 
+- make
+- cd python
+- python setup.py install
+
+## 
+The CSM is designed so that plugins with a common insterface are dynamically
+loaded.  This wrapper is designed to continue that philosophy. Therefore,
+loading an implementation of the interface is a little different than a
+standard python import.
+
+```python
+import csmapi
+import ctypes
+
+# THis dynamically registers this plugin with the CSM API.
+lib = ctypes.CDLL('path_to_the_libusgscsm.so')
+
+# The two methods that are implemented are getList and findPlugin
+plugin_list = csmapi.Plugin.getList()
+
+# Should be 2 assuming the USGS CSM-CameraModel was used
+print(len(plugin_list))
+```
+
+## Issues
+The dynamic cast from the model up the inheretance tree to RasterGM has not
+yet been implemented.  The test_functional.py (in tests) demonstrates how the
+returned object is a pointer to a Model. This needs to be dynamically cast (I
+think with a %factory directive) to the RasterGM class that contains the full
+suite of methods.
+
+
+```