Added further tests, some of which will fail using the older sqrt
Added further tests, some of which will fail using the older sqrt

rchiorean/bignumber.js,80xer/bignumber.js,rchiorean/bignumber.js,MikeMcl/bignumber.js,80xer/bignumber.js,MikeMcl/bignumber.js,80xer/bignumber.js,rchiorean/bignumber.js,MikeMcl/bignumber.js