Add option to disable automatic update (check).

Please, add an option to disable the automatic update check performed on every start of SourceTree.

I'm using SourceTree on a machine that is not connected to the internet. On every start, an error is shown that SourceTree failed to check for updates. I worked around it by modifying the AutoUpdater setting in SourceTree.exe.config but that does not seem like a supported way. Also, this removes the "Update" section from settings and the "Check now" button.

Not having an internet connection is one reason why one might not want to automatically update an app. Thinks that come to my mind:

• Corporate policies often do not allow automatic updates. Did you hear about the Trojan infected version of the Avidemux installer that happened this month? Now imagine if this happens to an automatically updated tool. That's only one reason for these policies.
• One might not want to get the work environment changed during critical phases of the development process. Do you have deadlines? I do.
• Some people prefer to not be the first to use a new version. If you're like me, you tend to run into issues. I switched to 2.x with 2.0.20.1 and even though I really like the speed bump (and no longer having selection issues in the lists), the blurry text (SRCTREEWIN-7085) makes me feel like having motion sickness. It's so annoying that I think about downgrading. Please, don't force me to use the latest version.
• Limited internet connections. Have you ever works offside? With a volume based plan? Like 100MB/week? Via EDGE? Every network packet counts. Trust me.
• Privacy concerns. (On Mac, I use LittleSnitch to enforce privacy settings. Errors due to unreachable update servers are annoying.)
• …

You get the idea: There are reasons for having auto-update turned off.