Identicons working in most lists, but not working for new items yet.

There are no settings yet.
Identicons now in new messages and in the From combobox.

[Broadcast Subscribers] gets the Bitmessage Icon for identification. This is hard-coded now, I would favour to put [Broadcast Subscribers] as a fixed item into the Address Book, so you can set an avatar as soon as i implement avatars.

Still no options yet: There will be an option to disable Identicons and Avatars separately. Another option will be for the suffix (to mimic adresses like "BM-...@bitmessage.ch" or to add a personal "salt" to prevent identicon attacks where someone creates an address with an identicon that looks alike the one of a known address). Also, identicon size (coupled with row height) should be available, but is of low priority.

Next step (after the settings) is to load specific avatars for each address.
quoted out the BSD licensed code (as i didn't get it to work properly yet)
now it should also work with the other identicon file
More informative "message truncated" text that tells users what to do to
view the full message.
Fix German translation of max difficulty tab
add api method addChan

This solves issue #484
Updated to work with QPixmap instead of PIL!

The original source is licensed under a BSD-License, so it should be fine to use.
...
nonfunctional identicon settings-GUI
avatarize
load avatar from file
- "set avatar" via context menu
- remove avatar by canceling "set avatar"
- get FROM address labels also from YourIdentities
- additional identicon type "empty" if you want to have a placeholder
- place image named 'default.*' to display a generic user icon as fallback
- place image named '[Broadcast Subscribers].*' to set the icon for broadcasts
- GUI settings done
removed bug: sent icon wrongly put into column 0 instead of 1
Merge branch 'upstream/master'

Conflicts:
	src/bitmessageqt/__init__.py
	src/bitmessageqt/bitmessageui.py
	src/bitmessageqt/settings.py
	src/bitmessageqt/settings.ui
	src/helper_startup.py
- add the settings also for old users
Merge branch 'master' of https://github.com/Bitmessage/PyBitmessage
Change the accepted address versions

Update _verifyAddress to accept version 4.