Add option for timeout in selfupgrade command

[grantholle]

Upgrading from a server within China was brutally slow. It couldn't update without timing out. This adds an option on the selfupgrade command to accommodate a timeout value for downloading the update.

[mahagr]

Default timeout should be at least 30 seconds IMHO.

[grantholle]

15 is the default in the Response class, which is what I based the default on here. I agree that 15 is pretty small.

[mahagr]

This one looks good to me.

I would still raise the default timeout limit to 30 seconds as your connection may be slow.

[grantholle]

Raised it to 30

[grantholle]

Any word on getting this approved?

[rhukster]

Merged!