Hash: Rename SHA->SHA1 and RIPEMD->RIPEMD160 (1/2)

These algorithm names were confusing, because there are actually
algorithms called "SHA" (a.k.a. SHA-0) and "RIPEMD" (the original
version).

This commit just renames the modules, with no backward-compatibility
support.
Hash: Rename SHA->SHA1 and RIPEMD->RIPEMD160 (2/2)

These algorithm names were confusing, because there are actually
algorithms called "SHA" (a.k.a. SHA-0) and "RIPEMD" (the original
version).

This commit adds backward-compatibility support for the old
Crypto.Hash.SHA and Crypto.Hash.RIPEMD modules.
Hash: Remove "oid" attributes; add "name" attribute

In PyCrypto v2.5, the "oid" attribute was added to hash objects.  In
retrospect, this was not a good idea, since the OID is not really a
property of the hash algorithm, it's a protocol-specific identifer for
the hash functions.  PKCS#1 v1.5 uses it, but other protocols (e.g.
OpenPGP, DNSSEC, SSH, etc.) use different identifiers, and it doesn't make
sense to add these to Crypto.Hash.* every time a new algorithm is added.

This also has the benefit of being compatible with the Python standard
library's "hashlib" objects, which also have a name attribute.
Hash: Speed up initialization by removing pure-Python wrappers

The pure Python wrappers around Crypto.Hash.* were convenient, but they
slowed down hash initialization by 4-7x.