PhutilServiceProfiler: unified logging for service calls

Summary:
Implements a central dispatcher for service calls so we can get unified logging
without adding custom trace modes to every service call generator.

Also implements phutil_deprecated() for marking things deprecated, and
phutil_passthru() which is a profiled passthru() (see T71).

Test Plan:
Ran included test script.

Reviewed By: aran
Reviewers: tuomaspelkonen, jungejason, aran
CC: aran, epriestley
Differential Revision: 285