Merge branch 'nd/http-fetch-shallow-fix' into maint

Merge branch 'nd/http-fetch-shallow-fix' into maint

Attempting to deepen a shallow repository by fetching over smart
HTTP transport failed in the protocol exchange, when no-done
extension was used.  The fetching side waited for the list of
shallow boundary commits after the sending end stopped talking to
it.

* nd/http-fetch-shallow-fix:
  t5537: move http tests out to t5539
  fetch-pack: fix deepen shallow over smart http with no-done cap
  protocol-capabilities.txt: document no-done
  protocol-capabilities.txt: refer multi_ack_detailed back to pack-protocol.txt
  pack-protocol.txt: clarify 'obj-id' in the last ACK after 'done'
  test: rename http fetch and push test files
  tests: auto-set LIB_HTTPD_PORT from test name