pidgin/pidgin

Install our appdata file to $(datadir)/metainfo as that change was made a long time ago

This patch originates from Lars Wendler from Gentoo

https://gitweb.gentoo.org/repo/gentoo.git/commit/net-im/pidgin/files/pidgin-2.13.0-metainfo.patch?id=2dd6c1852251b5b67c3045badf173be9535b97a9

Testing Done:
Installed to a prefix and verified the file ended up in `$prefix/share/metainfo`

Reviewed at https://reviews.imfreedom.org/r/607/
#error "This is file is not a valid C code"
/* This file contains some of the macros from other header files as
function declarations. This does not make sense in C, but it
provides type information for the dbus-analyze-functions.py
program, which makes these macros callable by DBUS. */
/* blist.h */
gboolean PURPLE_BLIST_NODE_IS_CHAT(PurpleBlistNode *node);
gboolean PURPLE_BLIST_NODE_IS_BUDDY(PurpleBlistNode *node);
gboolean PURPLE_BLIST_NODE_IS_CONTACT(PurpleBlistNode *node);
gboolean PURPLE_BLIST_NODE_IS_GROUP(PurpleBlistNode *node);
gboolean PURPLE_BUDDY_IS_ONLINE(PurpleBuddy *buddy);
gboolean PURPLE_BLIST_NODE_HAS_FLAG(PurpleBlistNode *node, int flags);
gboolean PURPLE_BLIST_NODE_SHOULD_SAVE(PurpleBlistNode *node);
/* connection.h */
gboolean PURPLE_CONNECTION_IS_CONNECTED(PurpleConnection *connection);
gboolean PURPLE_CONNECTION_IS_VALID(PurpleConnection *connection);
/* conversation.h */
PurpleConvIm *PURPLE_CONV_IM(const PurpleConversation *conversation);
PurpleConvIm *PURPLE_CONV_CHAT(const PurpleConversation *conversation);