pull: allow a generic way to pass parameters to the pull operation We have been feeling the need for this in extensions for quite some time. This will be used to pass remote bookmark information around in the next changesets.

pull: skip pulling remote bookmarks with bundle2 if a value already exists For efficiency and consistency purpose, remote bookmarks, retrieved at the time the pull command code is doing lookup, will be reused during the core pull operation. A second step toward this is to avoid requesting bookmark information in the bundle 2 if we already have them locally.

pull: skip pulling remote bookmarks with bundle1 if a value already exist For efficiency and consistency purpose, remote bookmarks, retrieved at the time the pull command code is doing lookup, will be reused during the core pull operation. A first step toward this is to setup the logic avoiding pulling the data again during the discovery phase if some have already been provided.

test: pull through http when testing for race conditions The http server is stateless giving more occasion for race. We switch the test to http before adding extra cases tests.