Implement support for new security policies

* Minimum complex characters
* Password history (i.e. disallow re-use of past n passwords)
* Password expiration
* Password expiration is NOT yet supported in the framework; there
  is a TODO in this CL and a trivial change will be needed when
  support arrives; for now, we report this as unsupported
* The two implemented policies are testable

Change-Id: I477adbc000577c57d1ab1788378c97a60018c10c
1 file changed