Previously to this, a level would be considered "not generated" if no level providers registered as valid for that directory. This caused astonishing behaviour when the user's world has, for example, a mixture of .mca and .mcr region files - the world would instead get _re-generated_ according to the default level format, which might or might not load the existing regions depending on the format used for generation. This behaviour is utterly absurd.
This changes the behaviour of the generated check to check for a non-empty directory in the given path. Non-empty directories without recognized world files in them are now considered to have an unknown format.
This is necessary because the stupid client constantly spams right-click actions if you carry on trying to eat/throw/whatever the item when cooldown is in effect. Therefore ender pearls would be fired like machine guns without these checks server side.
this was caused by abe5d94d5b because player's lastBlah wasn't getting updated anymore.
Player movement handling really needs cleaning up, but for now this fixes the issue.
save() calls saveChunks() which saves any chunks found to be modified. But chunk unloading does this anyway, so it's better to unload first and then trigger the save mechanism, to avoid saving chunks twice.
This supports vanilla placement of paintings, with overlap and collision checking.
Paintings are removed when a block is placed inside them or if any of their supporting blocks are removed.
As per vanilla, a random painting is chosen from the largest subset that will fit into the given space.
it appears that errors are occurring in the exception handler when handling corrupted regions, leaving regions in the provider index with incomplete location tables. This causes strange-looking errors later down the line.
This moves the region assignment to the end of the condition to avoid leaving incomplete/corrupted regions in the location table when errors occur.
