Fix some jshint issues.
Remove 32-bit message length limitation.
Reorganize code with public API at top.
Minor doc indent clean up.
Add note about message length limitation.
Clean up docs about padding and use binary mod.
Simplify 32-bit clamping.
Simplify 32-bit clamping.
Use |0 instead of Math.floor.
Remove 56-bit message length limitation on sha-256.
Remove 56-bit limitations on sha1 and md5; bug fix sha256.
Fix comment.
Add support for SHA-512, SHA-384, SHA-512/224, and SHA-512/256.