MFH: r445182 r447854

Update to 4.2.2

Changes: https://www.mercurial-scm.org/wiki/WhatsNew

Update to 4.3.1

• Strip shared library
• Use PORTDOCS

Changes: https://www.mercurial-scm.org/wiki/WhatsNew
Security: 1d33cdee-7f6b-11e7-a9b5-3debb10a6871

Approved by: ports-secteam (with hat)