Merge branch 'jc/abbrev-auto'

Merge branch 'jc/abbrev-auto'

"git push" and "git fetch" reports from what old object to what new
object each ref was updated, using abbreviated refnames, and they
attempt to align the columns for this and other pieces of
information.  The way these codepaths compute how many display
columns to allocate for the object names portion of this output has
been updated to match the recent "auto scale the default
abbreviation length" change.

* jc/abbrev-auto:
  transport: compute summary-width dynamically
  transport: allow summary-width to be computed dynamically
  fetch: pass summary_width down the callchain
  transport: pass summary_width down the callchain