R1:75bc86589f10

Add date range filtering for activity, push, and pull logs

Summary: Ref T13049. This is just a general nice-to-have so you don't have to export a 300MB file if you want to check the last month of data or whatever.

Test Plan: Applied filters to all three logs, got appropriate date-range result sets.

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T13049

Differential Revision: https://secure.phabricator.com/D18970