Bump to 0.5.1

Revamp the OS X signing and build process

This properly signs with mac v2 certificates so that the desktop
app appears verified on OS X 10.9+. We are forced to sign on a
10.9+ machine, but we want to build on 10.6 in order to run on
the widest types of OSes possible. So, we scp the Zulip.app bundle
to a 10.9+ machine during the build process, and then scp it back
after signing.

We also now copy Info.plist files for the frameworks we bundle with
our app, a new requirement by Apple for the v2 signing to be successful

Bump to 0.4.4

Debian changelog for 0.4.4

Changelog for debian 0.4.3

Don't show 'Start at Login' option on linux, as we don't support it

Bump to 0.4.2

Upload images using QHttpMimeData in OS X <= 10.7

zulip-desktop Debian release 0.4.0

Bump to 0.3.10