exchange: expand usage of getchangegroupraw The 'getchangegroupraw' is very simple (two lines) so we inline it in its only caller. This exposes the 'outgoing' object of the part generator function, allowing us to add information on the number of changesets contained in the part in a later changeset. Such information is useful for progress bar.

getbundle: have a single getchangegroupraw call site Having a single call site will simplify the code and help with coming refactoring.

phases: abort the whole push if phases fail to update (BC) When using bundle2, the phase pushkey parts are now made mandatory. As a result, failure to update the bookmark server side will result in the transaction being aborted.

bookmarks: abort the whole push if bookmarks fails to update (BC) When using bundle2, the bookmark's pushkey parts are now made mandatory. As a result failure to update the bookmark server side will result in the transaction being aborted.

httppeer: allow extensions to replace urllib2.Request The authentication library my extension wants to use requires using a different opener and a different request builder. This change pulls the call to urllib2.Request out so that my extension can replace it just like it can replace urlopener.

progress: move all logic altering the ui object logic in mercurial.ui The ui object can take care of its progress object logic by itself. test-subrepo-recursion is modified because it is a bit sensitive to the "no progress bar" default. It will become unnecessary in the next step when progress will be on by default in core.