* crypto/merkle: Remove byter in favor of plain byte slices
This PR is fully backwards compatible in terms of function output!
(The Go API differs though) The only test case changes was to refactor
it to be table driven.
* Update godocs per review comments
except now we calculate the max size using the maxPacketMsgSize()
function, which frees developers from having to know amino encoding
details.
plus, 10 additional bytes are added to leave the room for amino upgrades
(both making it more efficient / less efficient)
