wireprotoserver: rename p to proto
To aid readability. And to make it easier to search the code base
for protocol instances.
Differential Revision: https://phab.mercurial-scm.org/D1982
wireprotoserver: add some blank lines between methods
Let's make this file slightly easier to read.
Differential Revision: https://phab.mercurial-scm.org/D1981