Improper parsing of ".old" suffix

[dghodgson]

If the world-container option in bukkit.yml is set to the same directory as ROOT_PATH/WORLD_DIR, then when the mcrd_load() function goes to load the ramdisk it moves some folders and copies others, and only appends ".old" to some folders. This problem is probably un-related to the world-container option, but I only noticed it after using that feature.

For example, I had the following world folders in the WORLD_DIR :

world
world_nether
world_the_end
world_old

As you might have guessed, the problem goes away when the "world_old" folder is removed from the WORLD_DIR. Clearly we need to be a little more strict with how we parse folder names in the script. We'll have to look over the regular expressions again. It also wouldn't be a bad idea to scan for folders with potentially problematic names, and warn the user before exiting if any are found. Or possibly just have the script take care of the problem by itself.

We should also make sure to add a warning to the documentation later on about properly naming world files.

[WillHaggerty]

It is searching for ".[0-9][0-9]" so folders like .00 to .99 are ignored. The regex definitely needs to be cleaned up.