Structure of the math_stat module

The math_stat package is divided into lower and upper parts, where compilation
of a part is only dependent parts below it.

1) Lower Part
files: GenIndexHtml.scala, GenReadmeHtml.scala, package.scala, ReplaceOne.scala, Replace.scala, UpVersion.scala
packages: util, math, scala2d

2) Upper Part
packages: linalgebra, par, random, plot, stat, tenalgebra

With sbt may compile parts one by one by using "chmod 000".
> chmod 000 linalgebra par random plot stat tenalgebra
> chmod 700 linalgebra par random plot stat tenalgebra