Update textproc/coccigrep to 1.16

pkgsrc changes:
- Switch MASTER_SITES to MASTER_SITE_GITHUB that also contains newer
  releases
- Delete PYTHON_VERSIONS_INCOMPATIBLE, now coccigrep is compatible
  also with Python 3.

Changes:
1.16
----
- Add support for Python 3.4

1.15
----
- Add Python 3 support

1.14
----
- Various bug fixes and improvements

(leot)