* Update a index page.
* Check the convergence rate for spatial discretization in global shallow water model with DG method.

commit 420ec217b92cfbf188e383c676220e8f049dd8f5
Author: Yuta Kawai <ykawai@gfd-dennou.org>
Date:   Wed Dec 3 13:14:45 2014 +0900

    * Replace Gauss-Lobatto quadrature with gauss Legendre-Gauss quadrature in the line integral.

commit ae1b432fec0ab1371e4c855cc096cc839e1a2a32
Author: Yuta Kawai <ykawai@gfd-dennou.org>
Date:   Mon Dec 1 12:00:39 2014 +0900

    * Add a Roe numerical flux.
    * Modify the points and weights of cubatures on triangle.