std.hash: Ready for review (review manager needed)

[Johannes Pfau]

I think std.hash is ready for review now. I'm not sure if any other
module in the review queue is ready, but as there was no clear response
in the last review thread I assume we can start the std.hash review.

We still need a review manager though.

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std.hash.hash is a new module for Phobos providing a
uniform interface for hashes and checksums. It also provides some
useful helper functions to deal with this new API.

The std.hash package also includes a md5 implementation deprecating
std.md5 (in std.hash.md, adapted from std.md5), a new SHA1
implementation by redstar (in std.hash.sha) and a CRC32 implementation
(in std.hash.crc) based on and deprecating the crc32 module that's
shipped with phobos but not documented.

It only covers hashes which can process data incrementally (in
smaller buffers as opposed to all data at once).

Code:
https://github.com/jpf91/phobos/tree/newHash/std/hash
https://github.com/jpf91/phobos/compare/master...newHash

Docs:
http://dl.dropbox.com/u/24218791/d/phobos/std_hash_hash.html
http://dl.dropbox.com/u/24218791/d/phobos/std_hash_md.html
http://dl.dropbox.com/u/24218791/d/phobos/std_hash_sha.html
http://dl.dropbox.com/u/24218791/d/phobos/std_hash_crc.html