(needs careful review)

Attempt to improve performance.

Previous implementation happened to be very slow (on my laptop it took 5
minutes to read small pwsafe file and save it back). I profiled the code
and it turned out, this cost was totally dominated by the
Crypt::PWSafe3::random function (which on every call accesses system
random seed).

I replaced it with Bytes::Random::Secure which seeds using OS crypto but
afterwards uses embedded generator. Performance improvement is drastical,
the same read&save takes about half a second on the same laptop.

Makefile.PL

@@ -12,6 +12,7 @@ WriteMakefile(
 				  'Crypt::Random'  => 1.25,
 				  'Data::UUID'     => 1.217,
 				  'Shell'          => 0.5,
+                                  'Bytes::Random::Secure' => 0.09,
 				},
 	      'AUTHOR'       => 'Thomas Linden <tlinden@cpan.org>',
 	      'clean'        => {

lib/Crypt/PWSafe3.pm

@@ -621,12 +621,19 @@ sub writebytes {
   }
 }
 
+# This is original, very slow random
+#sub random {
+#  #
+#  # helper, return some secure random bytes
+#  my($this, $len) = @_;
+#  my $bits = makerandom(Size => 256, Strength => 1);
+#  return substr($bits, 0, $len);
+#}
+
+use Bytes::Random::Secure qw(random_bytes random_bytes_hex);
 sub random {
-  #
-  # helper, return some secure random bytes
   my($this, $len) = @_;
-  my $bits = makerandom(Size => 256, Strength => 1);
-  return substr($bits, 0, $len);
+  return random_bytes($len);
 }
 
 sub getheader {