pidgin/pidgin

Remove PidginWindow as it wasn't used and clean up some old PidginWindow -> PidginConvWindow that were previous missed.

2021-07-22, Gary Kramlich
2032d26a8d6b
Remove PidginWindow as it wasn't used and clean up some old PidginWindow -> PidginConvWindow that were previous missed.

Testing Done:
Compiled, built the pidgin docs, and pidgin.pot.

Reviewed at https://reviews.imfreedom.org/r/826/
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