Merge commit '36adc36' into dtls

* commit '36adc36':
  Add support for getrandom()
  Use library default for trunc-hmac in ssl_client2
  Make truncated hmac a runtime option server-side
  Fix portability issue in script
  Specific error for suites in common but none good
  Prefer SHA-1 certificates for pre-1.2 clients
  Some more refactoring/tuning.
  Minor refactoring

Conflicts:
	include/polarssl/error.h
	include/polarssl/ssl.h
	library/error.c