Include configuration options to suppress messages

Excellent module. The interface is much easier to use than the release monitor, and I love the links you've put in the table display.

My request here is for a way to suppress the warning messages you're giving. In some cases I've intentionally chosen the dev branches because they're more up to date than actual releases. One release particularly (privatemsg) I've rolled back to a previous version because the latest broke my install. I think it's enough to show the error in the status report without giving me a fat red error message on every administration page.

It would be nice to tweak the settings on this, and maybe to suppress any sort of warning for dev versions.