pidgin/pidgin

A handful of random cleanups in PidginConversation and PidginConvWindow

Testing Done:
Built and ran locally.

Reviewed at https://reviews.imfreedom.org/r/411/
syntax: glob
.*.swp
.DS_Store
.flatpak-builder
*.pyc
*~
\#*\#
subprojects/*/
syntax: regexp
^build(.+)?\/
win32-install-dir(\.release)?