Merge branch 'maint'

Merge branch 'maint'

* maint:
  git-svn: don't attempt to spawn pager if we don't want one
  Supplant the "while case ... break ;; esac" idiom
  User Manual: add a chapter for submodules
  user-manual: don't assume refs are stored under .git/refs
  Detect exec bit in more cases.
  Conjugate "search" correctly in the git-prune-packed man page.
  Move the paragraph specifying where the .idx and .pack files should be
  Documentation/git-lost-found.txt: drop unnecessarily duplicated name.