Fancy regex for version matching

Bukkit and Spigot both give funny versions (in this case, git-Spigot-1.7.2-R0.1-81-gae87ca8 (MC: 1.7.2)), whereas vanilla just sends the version number. (1.7.2). Pull *a* version number out of the string. Not guaranteed to be correct, but works for now on all 3.