movfun: movmin

[Juan Pablo Carbajal]

Dear all,

A first version of movmin is implemented in the movfun package

https://bitbucket.org/KaKiLa/movfun/src

A review is now in order, if anyone has time to do it. When this
function is polished, all the other mov* functions are implemented the
same way.

The critical points (check issues) are parsing of arguments (can't
check with the other software), and compatibility (name of options,
window length and asymmetry, etc...). Related to the later, note how I
named the boundary condition (now called Endpoints) arbitrarily,
without know what the other software did, I can fix that now.

Thanks