REST fix: show updated message as long as the object is updated.

previously, we only check if the last update succeeded or not, which is not
that right.

without this, t/web/command_line.t will fail on perl 5.18.0 because of the new
*random* results of hash's keys().
compare ref type first to make sure $entry_ref is not weirdly overloaded

one snippet:

    use Math::BigInt;
    no strict 'refs';
    # $round_mode = bless( do{\(my $o = 'even')}, 'Math::BigInt' );
    my $round_mode = *{'Math::BigInt::round_mode'}{SCALAR};
    print 'ok' if $round_mode;

because Math::BigInt overloads "bool" operation, the "if $round_mode" dies
with message "Not a HASH reference".

we do similar GLOB thing in RT::Config::__GetNameByRef, but before perl 5.18,
we can always find the right Name before checking "Math::Big::Int::round_mode"
thanks to the consistent hash's keys() behavior.

hash's keys() behavior has been changed since perl 5.18:

   Hash randomization
    The seed used by Perl's hash function is now random. This means that the
    order which keys/values will be returned from functions like "keys()",
    "values()", and "each()" will differ from run to run.

i.e. we might reach "Math::Big::Int::round_mode" in RT::Config::__GetNameByRef
since perl 5.18, so we need to make sure it won't die, that's the reason we do
the extra check before the "bool" operation("next unless $entry_ref;")

Math::BigInt is require by GnuPG::Interface.