Add RootHash JSON parameter.
Remove Spanshopt API method.
Add support on genProof/checkProof/dump to specify the RootHash
Refactory of some code
Signed-off-by: p4u <p4u@dabax.net>
New iden3 merkleTree implementation is not longer compatible. Until new
documentation is availabl and vocdoni code is adapted, use frozen
version of go-iden3 implementation.