pidgin/pidgin

Rename presence.[ch] to purplepresence.[ch], fix some docs, and other tweaks.

2020-11-01, Gary Kramlich
b82c365e04e8
Rename presence.[ch] to purplepresence.[ch], fix some docs, and other tweaks.

Testing Done:
Build, ran, and tested a bonjour account.

Reviewed at https://reviews.imfreedom.org/r/185/
libpurple/data/purple-url-handler.desktop.in
libpurple/protocols/null/nullprpl.c
pidgin/data/im.pidgin.Pidgin.desktop.in
sub/libpurple/data/purple-url-handler.desktop.in
sub/libpurple/protocols/null/nullprpl.c
sub/pidgin/data/im.pidgin.Pidgin.desktop.in