Check how re-extract of translation strings and upload to transifex works

[rufuspollock]

Need to check how well our process works when we do another extraction of strings. In particular would hope not too much of existing translations get blown away.

[rufuspollock]

Extraction worked quite well (even with our use of msgcat).

In addition have uploaded to transifex and result was quite promising:

• Italian translation (at 100%) dropped to 95% and this mostly because of a few sizable paragraphs with minor changes.

Aside: @timClicks given this effect of minor changes worth documenting for translators that this can happen - viz minor changes lead to discarding of translation (because computers do not do language comprehenesion!). Thus, even a trivial change to a paragraph leads to that no longer being translated and old translation thrown away. They should therefore first check old translation to see if that can be re-used (they should be able to find translation in their languages po file here on github).

Aside: that suggests another important rule. Never update transifex with a new pot without first downloading most recent versions of all translations and integrating ...