[CSI] sqrt() and rand() implementations

[Mikhail Nesterenko]

For the curious,

Here is an explanation of

   https://www.codeproject.com/Articles/570700/SquareplusRootplusalgorithmplusforplusC

and implementation of sqrt()

   http://www.netlib.org/fdlibm/e_sqrt.c


Here is the explanation of rand() algorithm

     https://en.wikipedia.org/wiki/Linear_congruential_generator

and its implementation:

    https://sourceware.org/git/?p=glibc.git;a=blob;f=stdlib/random_r.c;hb=glibc-2.15

Thanks,
-- 
Mikhail