Pidgin 2.13.0

Libpurple:
Unified string comparison.
Properlly shell escape URI's when opening them.
Fix a one byte buffer overread in function purple_markup_linkify.
Fix an issue were utf8 was incorrectly truncated which could lead to crashes as we were potentially feeding garbage into glib/gtk.
Libgnt:
Fixed build against curses 6.0 with opaque structs set.
Fixed a crash when resizing the window.
General:
Fixed bashism in autotools.
XMPP:
Show XEP-0066 OOB URLs in any message, not just headlines.
Fix a user after free.
Removed pipelining from BOSH connections.
Don't try to TLS already secured BOSH connections.
IRC:
Fix "Registration timeout" on SASL auth with InspIRCd servers (and possibly others not based on charybdis/ratbox/ircd-seven).
Fix issues with plugins that modify outgoing messages (such as the custom PART/QUIT feature of the IRC More plugin).
Fix IRC buffer handling.
Properly handle AUTHENTICATE as a normal command with server prefix.
Fix a crash caused by a use after free of the MOTD.
Fix an out of bounds read in irc_nick_skip_mode.
Fix a write of a single byte before the start of a buffer in irc_parse_ctcp.
Pidgin:
Better support for dark themes.
Fixed IPv6 links by not escaping []'s.
Only write buddy icons to the cache if they're not already cached.
Rejoin persistent chats after reconnect.
Made the WIN32 Transparency plugin work on all platforms.
Ensure search results buttons are labeled (Backport from de2d88e575ee).
Fix matching unicode smilies.
Correctly update mute/unmute status when the remote side mutes/unmutes us.
Rework the status icon blinking to not used deprecated API.
Don't allow adding a buddy to protocols that don't have an add_buddy callback.
Finch:
Fix handling of search results.
Voice & Video:
Port backend-fs to newer api for farstream relay-info property.