Extended glob pattern syntax:
o \ can now be used to quote special characters in the pattern
o [ can be used for ranges of characters ([bx] [a-c0-9] [^a] etc).
Also changed glob to return the matching glob instead of 1 when an
array is passed as the first (pattern) argument.
This can be used to remove some loops where you want to do different
things depending on which pattern matched.
Both these changes are incompatible.