grim/pidgin

cf58ec89b1e4
Rename message.[ch] to purplemessage.[ch]

Testing Done:
compiled and ran locally.

Reviewed at https://reviews.imfreedom.org/r/408/
For information on translating Pidgin, libpurple, and Finch, please see
our wiki page at https://developer.pidgin.im/wiki/TipsForTranslators