Update matrix-api compat
Add coercion functions
Check in sandbox of map-elements! implementation
Added sandbox work
Got element-map! working using lazy-seq technique.
Fix element-map/element-map! to comply with matrix-api contract. Lazy seq with context fns now not necessary.
Removed more unneeded code related to failed lazy-ctx-* etc. Moved do-elements-loop macro to matrix-api namespace