sysutils/py-supervisor: Update to 3.3.3

Update to 3.3.3, which fixes a security vulnerability (CVE-2017-11610).

While I'm here, level up port compliance, limiting changes to
a minimum.

Still TODO:

• Regenerate/verify patches
• Clarify/Add LICENSE ('BSD-derived')
• Fix/verify use of @[un]exec in pkg-plist

Changelog:

http://supervisord.org/changes.html

PR: 221539
Submitted by: Dani <i.dani outlook com>
Approved by: portmgr (maintainer timeout, 1 month)
Security: c9460380-81e3-11e7-93af-005056925db4
MFH: 2017Q3