Merge lp://qastaging/~chipaca/ubuntuone-client/very-basic-proxy-support-for-stable-1-4 into lp://qastaging/ubuntuone-client/stable-1-4

Quoting myself: the quality is low (not tdd! no tests! *eww*), and does not reflect how we like to do things, but it works for me and some might find it useful as a stopgap measure.

The way to use it is by setting the `HTTPS_PROXY` environment variable. This is done for you by GNOME proxy settings capplet.

> The way to use it is by setting the `HTTPS_PROXY` environment variable. This
> is done for you by GNOME proxy settings capplet.
... But it won't work for dbus-autostarted applications (checked in Maverick).

Here's why:
dbus-launch --exit-with-session gnome-session
gnome-session sets up HTTP proxy environment variables properly but syncdaemon is started by dbus which is not yet aware of these environment variables, therefore it won't see proxy configuration and will fail during connection.
It will work if the user launches /usr/lib/ubuntuone-client/ubuntuone-syncdaemon from the terminal but that is rather uncommon way of launching ubuntuone.

Are any other dbus-autostarted applications use network the way we do? How do they work then?

Chipaca, Syncdaemon will only work with system-wide proxy setting. But it needs to check 'http_proxy' and 'https_proxy' variables. For added twist it can also check for HTTP_PROXY and HTTPS_PROXY variables in case suddenly session-wide proxy starts working with dbus autostart

What about using GProxyResolver to retrieve proxy information?
http://developer.gnome.org/gio/2.26/GProxyResolver.html