working on stencil_example in c-tree environment
moving in more and more of stencil grid and asp to keep it independent
more stencil-grid
zillion incomplete changes to start looking at stencil grid in a ctree like fashion
Updating argument types for stencil example.
stub added for stencil grid visitor
merge
Merge branches 'master' and 'stencil_example' of https://github.com/ucb-sejits/ctree into stencil_example

Conflicts:
	ctree/jit.py
	examples/StencilGrid.py
	setup.py
Transformation of outer loop.

TODO:
  * Generate fresh variable logic for every loop.
  * Inner loop logic
Adding macro definitions and variable generation.

TODO: handle neighbors
Typo fix in stencil_kernel
Adding basic neighbor handling, fixing codegen.

TODO: Finish up neighbor loop.
Added array subscripts using macros.  TODO fix neighbors
Merge branch 'master' into stencil_example

Conflicts:
	ctree/c/codegen.py
	ctree/omp/codegen.py
	ctree/omp/nodes.py
	ctree/types.py
Update stencil_kernel for master interface changes.
Updating neighbor logic with proper conditionals.
Adding cast precedence.
Fixing paren logic for Cast
Bilateral filter working?
Bilateral filter working?