Merge branch 'maint'

* maint:
  remote: create fetch config lines with '+'
  push: allow unqualified dest refspecs to DWIM
  doc/git-gc: add a note about what is collected
  t5516: remove ambiguity test (1)
  Linked glossary from cvs-migration page
  write-tree: properly detect failure to write tree objects

diff --cc builtin-remote.c
Simple merge