This updates to implementation of gitattribute macros to be much more
similar to core git (albeit not 100%) and to handle expansion of
macros within macros, etc. It also cleans up the refcounting usage
with macros to be much cleaner.
Also, this adds a new vector function `git_vector_insert_sorted()`
which allows you to maintain a sorted list as you go. In order to
write that function, this changes the function `git__bsearch()` to
take a somewhat different set of parameters, although the core
functionality is still the same.
There were quite a few places were spaces were being used instead of
tabs. Try to catch them all. This should hopefully not break anything.
Except for `git blame`. Oh well.
