* Revert "default handler for 404 metrics to '__404__'"

This reverts commit 298b6aef2c55455b9b3db66eff8471187bb15857.

* Revert "update comments"

This reverts commit bec4a802d517edc9ce935efbf4981b0e81db509d.

* Revert "address comments"

This reverts commit 91ef5764d7add9005577da45df6f5b9f5aa4a52d.

* Revert "Add panic if metric was not registered."

This reverts commit 1f73b81977ab13a0c7cdbc24eaa1917b8712d68e.

* Revert "Improve Prometheus metrics"

This reverts commit 99001b6f8667b0aab74c6ab1b6090895c13df67d.