Support SIGINT for graceful daemon shutdown in libphutil

Summary: Ref T5855. Makes SIGINT mean "graceful shutdown" instead of being a synonym of SIGTERM.

Test Plan: See next revision.

Reviewers: btrahan, hach-que

Reviewed By: hach-que

Subscribers: epriestley

Maniphest Tasks: T5855

Differential Revision: https://secure.phabricator.com/D10227
Allow PhutilCommandString to escape as Powershell

Summary: This allows PhutilCommandString to escape as Powershell.

Test Plan: Unit tests

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D10249
Work around OSX after Yosemite no longer respecting CURLOPT_CAINFO

Summary: Fixes T5913. See discussion in that task.

Test Plan: Will make affected users in T5913 test.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: ide, epriestley

Maniphest Tasks: T5913

Differential Revision: https://secure.phabricator.com/D10315
Make sure TempFiles are destroyed after a PHP fatal error

Summary: Fixes T4284. Object destructors are not called after a fatal, but shutdown functions are.

Test Plan:
  - Created a test script which makes a temp file, then fatals.
  - Before patch, temp file was left around.
  - After patch, it is cleaned up.
  - Explicitly destroyed the tempfile in the script to verify that double-destruction is fine.
  - Removed fatal to verify that normal behavior works as expected.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T4284

Differential Revision: https://secure.phabricator.com/D10329