pidgin/pidgin

Remove a number of functions from gtkconv.c and gtkconvwin.c that aren't used anymore

Testing Done:
Compile only

Reviewed at https://reviews.imfreedom.org/r/907/
syntax: glob
.*.swp
.DS_Store
.flatpak-builder
*.pyc
*~
\#*\#
subprojects/*/
syntax: regexp
^build(.+)?\/
win32-install-dir(\.release)?
po\/pidgin\.pot$