dispatch: making all hg abortions be output with a specific label
This allows abortions to be highlighted specially and separately
from warnings - for instance, red is a reasonable color for when hg
aborts, but is overly dramatic for most warnings produced elsewhere.
Differential Revision: https://phab.mercurial-scm.org/D3967
ui: fix implicit unicode-to-bytes conversion introduced in 9df29b7c62cf
This is harmless, unless you try and run hg with HGUNICODEPEDANTRY
enabled. It's technically wrong, so let's go ahead and fix it.
Differential Revision: https://phab.mercurial-scm.org/D3989