CSymPy was renamed to SymEngine

[Ondřej Čertík]

Hi,

We renamed CSymPy to SymEngine.

The motivation was that CSymPy was a terrible name for a pure C++
library, and even a worse name for a Julia or Ruby library (with no
Python in it). SymEngine is the name of the C++ library now, and
CSymPy are just the Python wrappers (that use and work with SymPy).

Here is the new git repository address:

https://github.com/sympy/symengine

The old address (https://github.com/sympy/csympy) just redirects to
it. If you already have it checked out, the old git remotes will still
work, but I think it's a good idea to update them. You can rename your
own fork (but you don't have to), e.g. I renamed
https://github.com/certik/csympy to
https://github.com/certik/symengine, you do it in the "settings" tab.

Here are the PRs that rename things in the code:

https://github.com/sympy/symengine/pull/434 (merged)
https://github.com/sympy/symengine/pull/435 (waiting for Travis tests)

Here is the new gitter chat room:

https://gitter.im/sympy/symengine

If there is anything that breaks, please let us know. Unfortunately,
as Jason reported in another thread, gitter seems confused with the
old chat room. I reported a ticket to gitter about this.

Ondrej