Revert "add more precomputation to ecdsa signing"

This reverts commit 06dd166a82d465f6db297616b42446c8b4498efe.
Revert "Revert "add more precomputation to ecdsa signing""

This reverts commit 3747ba432336bf10191a63e84fbfead62e944ddb.
fix bug in unoptimized branch of code
add "small" switch to makefile
fix comparison of points