create alternative version for eigen values/vectors calculation

[bartekleon]

solution for #3014

This is a rough version. It might not work for all cases.

[bartekleon]

Checklist for implementation (unless decided otherwise):

• !! Ensure eigenvectors are correct, not only eigenvalues
• Ensure BigInt working
• Ensure BigNumber working
• Ensure Complex working

[gwhitney]

There are a lot of numerical issues in computing eigenvalues and eigenvectors. The current implementation at least attempts to handle those by "balancing" the matrix, etc. I doubt the solution is to start afresh with a totally new implementation (that will likely have its own collection of shortcomings). But let's keep this concept open until the issue in #2879 is resolved.