Fix decimal separator locale bug

statsd does NOT like numbers formatted like 0,1234 instead of 0.1234
PHP stupidly formats ALL numbers with locale aware decimal points
when simply interpolating floats:

// in German
$x = 0.1234;
// produces: see 0,1234
echo "see: $x";

I tried these options:

$x = sprintf("%F", $x); // Limited to 6 digits of precision
$x = sprintf("%.10F", $x); // Forced to 10 decimals always
$x = number_format($x, '.', 6, ''); // Forced to X decimals always

And strtr() ended up being the fastest and simplest.