Pootle: wrong 'critical errors'

[humdinger]

Whenever Pootle encounters a block with curly brackets, like

{0, plural, one{One new message} other{# new messages}}

it gets flagged as 'critical error: Python brace placehholders'

One can "mute" such an error, but it still shows up on various tables and it's confusing people.

Same for "XML tags" (where pointy brackets are involved) and "printf()" (for percent-symbols in e.g. variable names).

Can we remove those quality checks?