See https://github.com/anishathalye/dotbot/issues/282 and
https://github.com/anishathalye/dotbot/issues/315.
This patch simplifies the implementation, removing special-case handling
for the cases of zero matches and one match. Instead, any situation
where `glob: true` is specified and the path contains a glob character
(any of "?", "*", or "[") is treated as a glob case. The reason we check
both `use_glob` and `_has_glob_chars()` is to more gracefully handle the
case where the user has enabled globs by default, but most links do not
contain glob characters and should not be treated as globs.
Anish Athalye
Kurt McKee