Autopause if connection is lost

From time to time everybody has a short problem with the internet connection, the problem is that if you are using retroachievement and you don’t notice it, none of the achievement unlocked will remain unlocked after you close retroarch.

Retroachievement doesn’t store achievements to upload the information later (even though it would completely solve the problem) when the connection will return or at the next startup, so as a temporary solution a simple autopause if there’s a lack of connection should suffice.

Hopefully this can be added easily.