Add an option to show where DP was invoked

[janlimpens]

for instance
user>TRACK_DATAPRINTER=1 prove my_test.t
with the line

use Data::Printer;
my $test= 'x';
p $test, as => 'a test object';

could render as

a test object (@/home/user/my_test.t:3)
"x"

I spend way too much time hunting after useless ps I don't need anymore.

[garu]

This is a great idea. I have the same complaint and have been playing with it for a while but couldn't figure out a name for it. "track" seem perfect, thank you!