Reordered 2D

Added 2D Classic code -- combination of 2D PyClaw code and 2D 4.6 code when PyClaw code wasn't available.  Reordered array indices; also reordered loops to give memory-contiguous access to arrays in most places.  Fixed a bug in inlinelimiter.f90.  Changed functionality of claw2ez to do all of its own array allocation, as in the new 3D code, and added compatibility with run-time use_fwaves input parameter.  Added 2D advection and acoustics examples for use as test cases.