Marking import_warnings deprecated

As suggested by yanick, import_warnings is marked as
deprecated and will emit a warning on its use.

I've added myself as a contributor to the author file for work on
https://github.com/PerlDancer/Dancer/commit/9aee1c73365b876b7110253e6363a5f7a5078c02
add 'private_key' to the list of potentially sensitive keys
Merge pull request #892 from tomheady/devel

add 'private_key' to the list of potentially sensitive keys
Merge pull request #890 from symkat/import_warnings_deprecate

Marking import_warnings deprecated
Replace spurious character in Dancer::Session's POD.
Merge pull request #894 from racke/pr/dancer_session_pod_typo_fix

Replace spurious character in Dancer::Session's POD.
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
Merge branch 'v1.3111-grooming' into devel

preparations for the release
Issue 636

Added handling of binary files while testing file upoads in Dancer::Test.
removal of trailing whitespaces
update changelog
Merge branch 'pr/893' into devel

Fixes #893
Fixes #636
Document that response_exists and response_doesnt_exist are deprecated.