Merge pull request #212 from ahmadia/fix_test_euler2d_shockbubble

Skips test_euler2d_shockbubble.py if no scipy
added initial tarball from Gorunne
2D CUDACLAW with acoustics and shallow water solver.
Entropy fix not implemented.
Refactor for OS X/CUDA 5 Makefiles (incomplete)

Adding Makefile and starting to refactor some of the codes
to work with OS X.8 and CUDA 5.
Linux code path bug
building on OS X... and crashing
added glewInit call
Fixed the vertical reflective boundary conditions (order was reversed)
Fixed the way initial condition function related a row,column pair to an (x,y) coordinate.
Added a new file that solves the PDE without visuals:
CUDACLAW_main_noVis.cu
Both this file and cudaCLAW_main.cu have mains, so one has to choose which to include in the build.
Added a header file for the non visual main.
Updated some code in the visualizer part, removed dependence on glext.h.
Added some visual range adjustment functionality to view solution in different ranges (not get them cut off).
Added a snapshot functionality specifically for the non visual portion, with a matlab function script that takes the file name and the state to be displayed and shows it.
Fixing tip
needed fixes to get code building
Changes to boundary conditions, the convention is the following: the domain follows the natural cartesian coordinate system (x points right, y points up). The visual part or copy reverts this as OpenGL maps texture in reverse.
Time step adjustment: CFL condition check and revert step, correctly keep the simulation time.

These changes have slightly changes some of the signatures of main functions.
basic Cythonized CUDA/numpy interface up and running
A first pass at an interface definition

This is a first go at an interface definition using Cython's C++ syntax
to wrap at least one CUDAClaw struct.  I will eventually transplant the
CUDAClaw code into this subdirectory, but I'm still sorting out exactly
what files I need and what C++ interface code I still need to write.
building
interfaced cudaclaw into pyclaw (not working correctly)

this is a mock-up of a cudaclaw interface into pyclaw, with an example
shallow water 2D application.

Currently, almost nothing is supported beyond the basic controller interface,
in particular, the following are not available/modifiable:

* boundary conditions
* limiters
* Riemann solver
* CFL conditions
* variable time steps

The user should eventually be able to set initial conditions, adjust grid sizes, set a fixed dt, then view the output using pyclaw's visualization capabilities.

Currently, this code is *not* working correctly.
a few fixes, still broken
rename and cleanup for transplant into pyclaw directory structure
added missing limiters subdirectory