Form labels: Append colon if label ends with dot (at least in Czech)

[Vlastimil Zíma]

I have run into a feature which prevents label_suffix addition to the label if label ends with any of ':?.!'. The problem is that this is not a behaviour required at least in Czech. We use much more dots in shortcuts than English does and in case the label ends with such a shortcut the colon is required to be appended at the end.

Example: "Ulice a č.p." (Street and number) should be "Ulice a č.p.:"

I have discussed this on django-cs group ​https://groups.google.com/forum/#!topic/django-cs/5RG8AT2VmmA and it looks like a bug.

Proposed solution: Update the translation of ':?.!' to ':?!' in Czech.

[Claude Paroz]

We have purposefully set the suffix list to a translatable string, so as it can be overridden per language. The proposed solution is probably right, but then translations issues are not tracked here, just update the string on Transifex (now is a good time to target 1.8).