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
$ cat > a <<EOF
> a
> b
> c
> EOF
$ hg ci -Am adda
adding a
$ cat > a <<EOF
> d
> e
> f
> EOF
$ hg ci -m moda
$ hg diff --reverse -r0 -r1
diff -r 2855cdcfcbb7 -r 8e1805a3cf6e a
--- a/a Thu Jan 01 00:00:00 1970 +0000
+++ b/a Thu Jan 01 00:00:00 1970 +0000
@@ -1,3 +1,3 @@
-d
-e
-f
+a
+b
+c
$ cat >> a <<EOF
> g
> h
> EOF
$ hg diff --reverse --nodates
diff -r 2855cdcfcbb7 a
--- a/a
+++ b/a
@@ -1,5 +1,3 @@
d
e
f
-g
-h