declared, intstalled and added example for IsNotContainedInAnyHyperplane
declared, intstalled and added example for GeneratorOfAnElementNotContainedInAnyHyperplane
Code cleaning

Changed names of some variables.
Outsourced the Iteration in IsPrimeZeroDim for the infinite case.
Coding style
One missed changed variable.

Don't know how to put this afterwards in a former commit. Deleted 3 hours work the last time I tried to reverse the last commit.
Restricted RadicalOfIdeal for rings over perfect fields.
Installed a list ListOfNonLinearFactors in PrimaryDecompositionZeroDim

Saves all irreducible factors with degree higher than one.
Added some comments
Added examples for IsPrimeZeroDim, IsPrimaryZeroDim and PrimaryDecompositionZeroDim