Format conduit call information in ServiceProfiler

Summary: Mabye some day this will be pluggable. For now, add an entry to the big switch. See D7482.

Test Plan: Looked at "Services" tab.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D7483
Add "PhutilDirectedScalarGraph"

Summary: Ref T4068. I need a non-fancy version of this to topographically sort commits.

Test Plan: See next revision.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T4068

Differential Revision: https://secure.phabricator.com/D7517