Merge branch 'ab/i18n-basic'

Merge branch 'ab/i18n-basic'

* ab/i18n-basic:
  i18n: "make distclean" should clean up after "make pot"
  i18n: Makefile: "pot" target to extract messages marked for translation
  i18n: add stub Q_() wrapper for ngettext
  i18n: do not poison translations unless GIT_GETTEXT_POISON envvar is set
  i18n: add GETTEXT_POISON to simulate unfriendly translator
  i18n: add no-op _() and N_() wrappers
  commit, status: use status_printf{,_ln,_more} helpers
  commit: refer to commit template as s->fp
  wt-status: add helpers for printing wt-status lines

Conflicts:
	builtin/commit.c