next round of patches

[Justus Winter]

Hi :)

[PATCH 1/5] libihash: fix typo
[PATCH 2/5] libihash: add hurd_ihash_get_load

This also makes the description of binary percent more prominent.

[PATCH 3/5] libihash: add hurd_ihash_value_valid
[PATCH 4/5] libihash: optimize lookup-or-insert operations

I'm replacing the node caches in {ext2,fat,iso}fs with libihash.  This
change extends the API of libihash so that it can be used more
efficiently.

[PATCH 5/5] include: add lock-less reference counting primitives

Now with descriptive assertions (thanks Neal :), and two new
primitives: reference promotion and demotion.

Cheers,
Justus