Can't handle renamed resources on case insensitive filesystems.

GIT has quite a few issues concerning renamed files on case insensitive filesystems, such as Mac OS X's default HFS+.

For instance:

lhunath@Myst t $ git mv Foo foo fatal: destination exists, source=Foo, destination=foo

Moreover, when a repository contains Foo and foo in one commit and in a subsequent commit, "foo" is removed; "Foo" will also disappear when checking out the latter.

Most of these issues are likely just a result of the underlying file system's handling of GIT's commands; though considering that Mac OS X's default fs is case insensitive by default, and the Mac and Windows userbases combined are quite large; it might be very much appropriate to do a check for this (if needed) and handle renames (and other operations?) in a way that they would not cause conflicts on these file systems (eg. rename to a temporary filename first and then rename to destination).

In particular; these issues make it awfully painful to refactor Java class names from things like JndiUtils -> JNDIUtils.  Not only is it hard to get the commit INTO the repository correctly; it is also hard to check the commit OUT for somebody who has no idea any of this is needed.