Chebfun V5 release

[Nick Hale]

We are pleased to announce the release of Chebfun Version 5, available
for download at http://www.chebfun.org/download/

Version 5 has involved a complete rewrite of the code with a focus on
clarity to make it more accessible and extensible. The code is hosted
on GitHub (https://github.com/chebfun/), and we welcome new developers
to get involved.

To get a sense of the breadth and power of Chebfun, a good place to
start is by looking at our Examples at http://www.chebfun.org/examples/
or the introductory Guide at http://www.chebfun.org/docs/guide/

New features in V5 include:
- First official release of Chebfun2 for bivariate computing
- Powerful new bivariate rootfinding algorithms
- Major speedups of conv, polyfit, abs, inv, and pde15s
- O(nlogn) codes leg2cheb, cheb2leg for coefficient conversion
- Option for algorithms based on first kind Chebyshev points
- A Chebfun constructor option 'equi' for equispaced data
- A 'periodic' flag for Fourier interpolants instead of Chebyshev
- Ultraspherical spectral methods for ODEs
- Improved graphical interface (chebgui) for ODE capabilities

Please contact us with any questions/comments at he...@chebfun.org