Log Message:
Updated scrypt to 1.2.1.

Significant changes since 1.2.0:
* A new -v option instructs scrypt to print the key derivation parameters
  it has selected.
* A new --version option prints the version number of the scrypt utility.
* A new -P option make scrypt read the passphrase from standard input; this
  is designed for scripts which pipe a passphrase in from elsewhere.
* A new -f option makes 'scrypt dec' ignore the amount of memory or CPU time
  it thinks decrypting a file will take, and proceed anyway; this may be useful
  in cases where scrypt's estimation is wrong.
* The '-M maxmem' option now accepts "humanized" inputs, e.g., \ 
"-M 1GB".

There are also a variety of less visible changes: Performance improvements
in the SHA256 routines, minor bug and compiler warning fixes, the addition
of a test suite, and some minor code reorganization.