Merge branch 'master' into next

Merge branch 'master' into next

* master:
  Documentation: git-svn: fix trunk/fetch svn-remote key typo
  Mailmap: Allow empty email addresses to be mapped
  Cleanup warning about known issues in cvsimport documentation
  Documentation: Remove an odd "instead"
  send-email: ask_default should apply to all emails, not just the first
  send-email: don't attempt to prompt if tty is closed
  fix portability problem with IS_RUN_COMMAND_ERR
  Documentation: use "spurious .sp" XSLT if DOCBOOK_SUPPRESS_SP is set
  mailmap: resurrect lower-casing of email addresses
  builtin-clone.c: no need to strdup for setenv
  builtin-clone.c: make junk_pid static
  git-svn: add a double quiet option to hide git commits