[Bug 823495] Add MLT error logging.

[mythmon]

This does little more than actually record the errors that elasticutils spits out.

r?

[willkg]

Nit: This should probably be a DEBUG-level thing.

[willkg]

That one nit is my only minor issue. Otherwise this looks good.

Also, this brings to mind whether we should switch to using .format across the board instead of %. The two problems with .format are these:

1. It introduces a different syntax for variable replacement for localizers, so that might be an issue for using this with localized strings. We could probably check with Milos or Stas about whether this is an issue or not with Verbatim and what localizers expect/know.
2. python 2.6 doesn't support {} in .format strings--only python 2.7 does--so we'd need to be careful about that.

Anyhow, other than that, r+.

[rlr]

cool! what @willkg said.

[mythmon]

Switching this to DEBUG and landing.

Regarding .format vs %, I think that .format makes more sense for localization, because 'Hello, {name}' has more context than 'Hello, %s'. For this reason, I also think we should use name-based instead of index-based formatting. This is similar to how we use {{ jinja_variables }} in templates, and localizers have handled that fine.

[mythmon]

4d7583d

[willkg]

We shouldn't be doing 'Hello, %s.' It should be 'Hello, %(name)s.'. Ick.

Having said that, I just checked the docs and they actually say to use .format with kwargs. So, nix my concerns--we should be doing that:

https://kitsune.readthedocs.org/en/latest/localization.html#making-strings-localizable