Authentication for LSL scripts & the web servers they talk to

[CmpZ]

I adapted HMAC to LSL so scripts & web servers can authenticate each other.

The real write-up is http://cybertiggyr.com/fakemac.html

but here's the LSL

      string
      Fake_MAC( string secret, string message ) {
          string o_pad;
          string i_pad;

          o_pad = llSHA1String( secret + "ooo" );
          i_pad = llSHA1String( secret + "iii" );
          return llSHA1String( o_pad + llSHA1String( i_pad + message ) );
      }