magit-log-long-re: rename from magit-log-longline-re

Logs of type "long" do not consist of one long line per commit, as
opposite to a "short oneline" per entry.  They commit is represented
by *multiple* lines, which usually are *shorter* than those used by
logs of type "oneline".  The name of this variable probably used to
contain "longline" instead of "long" to achieve some misguided
consistency with "oneline"; fix that.
magit-wash-commit: lose whitespace and a comment
magit-wash-commit: simplify propertizing first line
magit-format-ref-labels: new function
magit-wash-log-line: use magit-format-ref-labels

This has to unfortunate but acceptable consequence that when there are
only "uninteresting" refs then, when showing a "long" log the revision
hash is abbreviated just if there were at least one "interesting" ref.
In the latter case we do so to make room for the displaying the refs,
in the former case we don't need to make room, but now do so anyway.
However that doesn't really matter.
magit-wash-commit: use magit-format-ref-labels

... to format the refs at the end of the first line, if any.
rename section "Revisions and Ranges" to just "Revisions"

It also contains things to related references and tags (and files);
a more generic "Revisions" serves better than a overprecise but
incorrect heading.  Also remove the subsection headings.
magit-format-rev-summary: new function

... replacing `magit-format-commit'.

Now the rev on "Head", "Rebasing", and "Applying" header lines
in Magit buffers is colorized like they are in most other places.
Merge branch 'pr/goodies'