You fix the class already. Nice.
I think if you were inspired and not reusing the code that is enough but I'm not a legal expert ;).
When testing Joss's library I found two bugs.
First is rare. Last correctly translated string is lost if there is a fuzzy comented string (#~ ).
The other is a bit specific too. His library doesn't distinguish same strings (same msgid) with different context (msgctxt).
More info on my modification:
bugs.mageia.org/show_bug.cgi?id=148
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