Revert to plain Ridders update
Revert to plain Ridders update

Now change to ridders rule which ensure that we never go out of (a,b)
interval seems unnecessary since we revert to bisection in this case.

Sadly that change was completely undocumented so it's difficult to
infer its real goal

bos/math-functions,bos/math-functions,Shimuuar/math-functions,Shimuuar/math-functions