* split the eigs function into multiple algorithms
* moved checks and coersions to eigs.js, made them more robust
* fix little bugs, make im and re more robust
* Implemented matrix balancing algorithm
* fix typos
* a draft of reduction to Hessenberg matrix
* finished implementation of reduction to Hessenberg
* fix Hessenberg elimination for complex numbers
* implemented non-shifted explicit QR algorithm for real matrices
* implemented vector computation, won't work untill usolve is fixed
* refactored to match yarn lint
* some minor changes
* solve merge conflicts
* refactored and re-fixed #1789
* some old uncommited changes
* fix small problems introduced by merging
* done some polishing
* improved jsdoc description of eigs
* little changes in jsdoc
Co-authored-by: Jos de Jong <wjosdejong@gmail.com>