Squashed 'vendor/tcloo-ext/' changes from d40f439..1e7b835

1e7b835 Fix a typo.
aadb2df Simplify the code a bit.
3a95cd0 Fix an issue where metaclasses where added in reverse order.
1093ce9 Always require TclOO.

git-subtree-dir: vendor/tcloo-ext
git-subtree-split: 1e7b8353b011f24033a818195a81a8299b01b96f
Merge commit '6753bc586300f70a63cf6ae59829b40e25030145'