vch -> buf
vch -> buf

The term "vch" comes from bitcoind, which uses C++ vectors, and vch refers to a
vector of characters, which is analagous to a buffer in node. In order to
retain the internal consistency of using "buf" everywhere in fullnode, I have
replaced "vch" with "buf".

ryanxcharles/fullnode,reddit/fullnode,martindale/fullnode,martindale/fullnode,ryanxcharles/fullnode