Merge branch 'cc/promisor-remote-capability' into seen

The "promisor-remote" capability mechanism has been updated to
allow the "partialCloneFilter" settings and the "token" value to be
communicated from the server side.

Comments?

* cc/promisor-remote-capability:
  promisor-remote: use string constants for 'name' and 'url' too
  promisor-remote: allow a client to check fields
  promisor-remote: refactor how we parse advertised fields
  promisor-remote: allow a server to advertise more fields
  promisor-remote: refactor to get rid of 'struct strvec'

diff --cc Documentation/gitprotocol-v2.adoc
Simple merge

diff --cc promisor-remote.c
Simple merge