Rename errant localization keys

Property files can look like "key=value", "key = value", "key:value", or
"key value". Fred only recognizes the first, so it can find unescaped
spaces in the middle of a key, whereas conformant parsers find
"key value=more value". Because of this, translators on Transifex are
presented with part of what Fred considerers the key as the start of the
value, and translating it changes the key Fred finds to something the
localization layer isn't queried for.
Add underscores to remaining languages
Merge branch 'localization-key-spaces' into next
Remove untranslated strings from translations

Because Transifex does not support this, it is string matching and
removes strings for which no translation is necessary.