Update compression type from gzip to zlib

Weechat changed the default keyword to zlib.  We should match this
change as well.
Add support for _nicklist_diff command

Weechat now sends diffs instead of full nicklist messages where
appropriate.  This was "forced" on clients in version 0.4.1-dev,
commit 86a8b9fb.

http://git.savannah.gnu.org/gitweb/?p=weechat.git;a=commitdiff;h=86a8b9fb
Replace WeeChat logo by the new one
Update pom.xml to work with latest android tools

aapt moved, so we need a newer version of the android-maven-plugin to
build properly.
Update weechat logo

Merge branch 'new-weechat-logo' of https://github.com/flashcode/weechat-android
See Pull Request #77
Update android-maven-plugin version to 3.6.0

Fixes compilation with r17 SDK, see:
https://code.google.com/p/maven-android-plugin/issues/detail?id=377
Merge pull request #78 from jspricke/maven-fix

Update android-maven-plugin version to 3.6.0