Rework usage of localization files

[Jummit]

In #311 I added two dialogs, and translating them using translation keys was a little tedious. The process of adding a caps-lock word instead of the text and then modifying a CSV file is not very beginner-friendly. I think it would be better if we would use the english sentence as a key, which would make it possible to not include it in the CSV file and still have it show up if no other translations have been found.

Before:

"keys","en","de"
"WAIT_STOP", "Wait, stop!", "Halt, warte!"

print(tr("WAIT_STOP")

After:

"keys","de"
"Wait, stop!", "Halt, warte!"

print(tr("Wait, stop!")

print(tr("More text")) # Not included in translation file, but prints correct text.

I think this is more scalable and intuitive than the previous process.

Of course this means that when modifying a key you have to check the translations, but I think that's better than having to modify the csv file for every translatable string.

I think it would be best if text effects like
[wave amp=50 freq=2]LEVEL:[rainbow freq=0.5 sat=1 val=20]%d[/rainbow] [/wave]
would be removed from the translation too.

This is worked on in #327

[lazerwalker]

Once we have Danger in place, I wonder if we could add a check that basically says "if a PR diff contains any modified tr() calls, throw an error if a translation CSV wasn't also edited"