push: more robust check for bundle fast path
When all changesets in the local repo are either being pushed or remotly known,
we can take a fast path when bundling changeset because we are certain all local
deltas are computed againts base known remotely.
So we have a check to detect this situation, when we did a bare push and nothing
was excluded.
In a coming refactoring, the discovery will run on filtered view and the content
of `outgoing.excluded` will just include unserved (secret) changeset not filtered by the
repoview used to call push (usually "visible"). So we need to check if there is
both no excluded changeset and nothing filtered by the current repoview.
$ hg init repo
$ cd repo
$ touch foo
$ hg ci -Am 'add foo'
adding foo
$ hg up -C null
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
this should be stored as a delta against rev 0
$ echo foo bar baz > foo
$ hg ci -Am 'add foo again'
adding foo
created new head
$ hg debugindex foo
rev offset length ..... linkrev nodeid p1 p2 (re)
0 0 0 ..... 0 b80de5d13875 000000000000 000000000000 (re)
1 0 24 ..... 1 0376abec49b8 000000000000 000000000000 (re)
$ cd ..