Pidgin 2.7.8

# General:
- Fix the exceptions in purple-remote on Python 2.6+. (Ari Pollak)

# Pidgin:
- When a conversation has reached the maximum limit on the number of smileys, display the text representation of the smiley properly when it contains HTML-escapable characters (e.g. "<3" was previously displayed as "&lt;3").
- Drop dependency on GdkGC and use Cairo instead.
- New UI hack to assist in first-time setup of Facebook accounts with icon from Jakub Szypulka.
- Don't hide the buddy list if there is no notification area in which to put the icon.

# libpurple:
- Fix multipart parsing when '=' is included in the boundary for purple_mime_document_parse. (Jakub Adam)

# AIM and ICQ:
- Buddies who unset their status message will now be correctly shown without a message in your buddy list.

# Gadu-Gadu:
- Updated our bundled libgadu and minimum requirement for external libgadu to 1.9.0.

# MSN:
- Stop showing ourselves in the list of endpoints that can be disconnected.
- Allow full-size display names, by not escaping (most) non-English characters.
- Fix receiving messages from users on Yahoo and other federated services.
- Correctly remove old endpoints from the list when they sign out.
- Add option to disable connections from multiple locations.
- Correctly update your own display name in the buddy list.
- Correctly show ourselves as offline in the buddy list when going invisible.
- Correctly update your own icon in the buddy list.
- Remove struct packing for better portability.

# XMPP:
- Terminate Jingle sessions with unsupported content types.