Tweak localelinter output and verification

* take into account untranslated strings
* show the strings that were compared so it's easier to see issues
  and false positives from the output

Minor problem is that since strings are unicode and consoles might
not be, it converts strings to ascii and replaces non-ascii characters
with ? which sucks for languages that aren't ascii-ish. That needs
some thought.
Yak-shaving on the localelinter

* can now lint entire directories
* only runs on .po files
* produces stats so it's easier to see problem locales
ES_LIVE_INDEXING should default to False in tests
[Bug 794236] product.title to _(product.title ...)