Adds ProfitStars to PoweredByMesos page.
Fixed display of table filter for empty tables.

Review: https://reviews.apache.org/r/17082
Add configuration check to libprocess for std::unique_ptr and std::move

Review:
First try to fix #1571. Propagate shutdown timeout to Executor and CommandExecutor via env variable. Remove escalation constant for command executor.
Second try to fix 1571.
Third try to fix 1571. Move shutdown adjust timeout logics into utility function, improve comments and style.
Fix build errors.
Add a comment about ShutdownProcess design.
Add tests for graceful shutdown.
Add and fix comments.
Fix graceful shutdown test on Linux.
Add more comments.
Update comments.
Rename functions adjusting timeouts; introduce a check; update comments.
Refactor timeout adjusting function.
Minor improvements in shutdown test.
Rename predicate for shutdown test.
Remove the force shutdown test.
Move implementation into the .cpp; update comment.
Add a test for the graceful shutdown.