update merkle tree and add sha utils

[HavekHD]

I am not a c++ expert so please review carefully before merging. I have not reviewed all of the sources thoroughly so the sha utils may be addressed somewhere else and not necessary.

This could also break pools since most are using the old merkle implementation. Please review fully and correct any mistakes I may have made or do not merge at all if it does not seem to be an improvement.

[J-Ttt]

Needs to be tested first

[HavekHD]

Do not merge I need to redefine the hasher function which should make it easier if we ever move from sha. I will update more over the weekend

[HavekHD]

Closed until further refined