Log Message:
Update ruby-listen to 3.0.3.

pkgsrc change: add pkg_alternatives support.

v3.0.3

Improvements

* #330 - fixed warnings on JRuby

v3.0.2

Bugfixes

* fix #328 - add missing require which crashed Listen on OSX (thanks to @noahsw \ 
for reporting)

v3.0.1

Bugfixes

* #325, #327 - fix regressions (allow Listen to run correctly without other
   deps + properly handle pause())

v3.0.0

KNOWN ISSUES

* #319, #258 - TCP is no longer part of Listen, and there's currently no
   alternative except downgrading to Listen 2.x

API CHANGES

* TCP functionality removed (Listen.on, Adapter::TCP,
  Adapter::TCP::Broadcaster, etc.)
* Listener#start should be used instead of Listener#unpause
* Listener#directories is no longer available
* Listener#options is no longer available as public API

IMPROVEMENTS

* Major performance improvements (CPU), especially for Polling
* Celluloid is no longer required by Listen (which means: better performance,
  less dependencies, less threads used, less version conflicts, easier
  debugging, less potential issues/bugs)
* TCP is no longer part of Listen (which means: more maintainable codebase and
  possibility to create much better TCP implementation without the tradeoffs)

Development

* major codebase rewrite
* better logging by default