repository_head_unborn: clear error when HEAD is unborn
Introduce failing test for conflict filtering in index
Ensure filters (i.e. CRLF) are applied when checking out conflict content
Don't copy buffer in checkout unless needed
p_lstat win32: don't canonicalize volume mounts

A reparse point that is an IO_REPARSE_TAG_MOUNT_POINT could be
a junction or an actual filesystem mount point.  (Who knew?)
If it's the latter, its reparse point will report the actual
volume information \??\Volume{GUID}\ and we should not attempt
to dereference that further, instead readlink should report
EINVAL since it's not a symlink / junction and its original
path was canonical.

Yes, really.
is_empty_dir (wi32): cope with empty mount points

FindFirstFile will fail with INVALID_HANDLE_VALUE if there are no
children to the given path, which can happen if the given path is a
file (and obviously has no children) or if the given path is an empty
mount point.  (Most directories have at least directory entries '.'
and '..', but ridiculously another volume mounted in another drive
letter's path space do not, and thus have nothing to enumerate.)

If FindFirstFile fails, check if this is a directory-like thing
(a mount point).
Add a test to make sure a new snapshot has the new value.
Change the length of the file so that the change is picked up.
Patch from @carlosmn to refresh the parent config before snapshotting.
Fixed memory leak in git_tag_delete()
travis ci: build maint branches and development'
config test: clean up memory leak
global: clean up openssl_locks on shutdown
Merge pull request #2655 from ethomson/v0.21.2

More backports to 0.21