moved basic stencils to stencil_code.library package, this will make it much easier to have examples, tests and benchmarks all use the same implementations instead of having multiple versions of everything
all example stencils in stencil_code.library package run from command line
cool way of generating a testable interior points slice
test_c_end_to_end retooled to use stencil_code.library package
made this test a little more generic, so it can be cut and paste into ocl and omp tests
Tests all work, but bilateral filter seems to be only equal within some interior region of the computed interior
Found nasty bug in ocl.py, when loading local_memory to include maximal ghost zone, clamping was incorrectly done on the max side, the ghost depth was being subtracted from the max, data should have been copied all the way up to the maximum size of the matrix

parameters had wrong defaults in bilateral filter, and testing of c ocl equivalence was missing

test files retooled to use new interior_points_slice convenience method