Compute caller seems to be time-consuming.

[jsimonet]

Related to #1, if seems that computing the caller is time-consuming.

Maybe is could be optional?

use Log::Any.add( Log::Any::Pipeline.new( :no-caller-category ) )

On or off by default?

[jsimonet]

I started a new branch to test new performance improvements features : https://github.com/jsimonet/log-any/tree/dev/perf