version of clamped vector load from nick-sandbox
updated clamped vector load code to use IR node make methods
test code for clamped vector load, for posterity
removing test app
Merge branch 'master' into clamped-vector-load
removed print statements and added a few comments to clamped vector load
removed environment variable check
Merge branch 'master' into clamped-vector-load
add python bindings (still have swig errors)
fix bugs in py bindings
builds but has problems still
Type codes were wrong in the docs.
Merge pull request #94 from steven-johnson/master

Add Func names to assertion failures in Function.cpp
Fixed comment in image_io.h
Added a second lesson to tutorial/

And updated the first one slightly.
Merge pull request #95 from steven-johnson/master

Changes to CodeGen_C to allow result to compile & run properly
merged with master and nick-sandbox
removed print statements
removed environment variable check in clamped vector load
Having the last pass be CSE pulled out constants that mess up codegen