add deprecation mention for 'after'

Fixes #880
Merge branch 'deprecate-after' into devel

Add deprecation note in the documentation of 'after' hook.

Fixes #880
add update_authors.pl

A small utility to harvest all the contributors to the project
contributors since last release
self-promotion to core team :-)
tally all the changes since last release
bumping version to v1.3111
cleaning MANIFEST