outgoing: fix possible filtering crash in outgoing (issue3814)

If there is no outgoiing changesets but we have filtered revision in outgoing.excluded
We run into a filtering related crash. The excluded revision should not be there
in the first place but discovery need cleanup in default, not stable.

--HG--
branch : stable
extra : source : e7b89b5127c2607bcaedf7c2fb0ea525df526ea6
merge with stable
merge crew heads
summary: test that current bookmark isn't shown

This exposes the current behavior in a test. A later change will make
summary show when the active bookmark has moved out from under us.

--HG--
extra : rebase_source : f4dcb9781e54e9982d4366e2d577dbf8a0bc7ac3
summary: simplify handling of active bookmark

--HG--
extra : rebase_source : e937b6b2d13975082619f6945a570dfdb9b44135
summary: show active bookmark even if not at current changeset

Before this change, 'hg summary' would not show the active bookmark
unless it pointed to the working directory parent. After this change, it
will show it in parentheses, like so:

parent: 18581:f0ff45fe6700 tip
 summary: simplify handling of active bookmark
branch: default
bookmarks: [crew]
commit: (clean)
update: (current)

--HG--
extra : rebase_source : e522bb36e0b75110adb95e4da443f42f06fe526b
summary: add missing space for updated active bookmark display