Numberize - treat numbers as perl does

Ability to treat the numbers as perl does
bson_encode({one => '1', 1}
will be the same as
bson_encode({one => 1}

There will be no need to do something like this:
my $var = $c->param('var');
$var+=0;

I think without that option perl programmers will have a headache in the real world. If it will be applied, we'll be able to add  a 'numberize' attribute for Mango::Collection. I've founded that word, but my English isn't good enough, so it may sound a little weird.

Surprisingly, when I changed the default value to 1, all tests had passed ok o_0. But I think it would be better to leave it as it is now.