Log Message:
p5-GStreamer: update to 0.20.

Overview of changes in GStreamer 0.20
=====================================

* GStreamer.pm: Announce/link to new GStreamer1 module
* README: Add note for and link to new GStreamer1 module
* copyright.pod: updated copyright year
* perl-GStreamer.doap: update project short description

Overview of changes in GStreamer 0.19
=====================================

* Avoid misusing the macro PL_na, thus preventing potential issues when
  GStreamer is used in conjunction with certain XS modules, among them
  XML::Parser and String::Approx.

Overview of changes in GStreamer 0.18
=====================================

* Add GStreamer::Buffer::data_ptr() to access the buffer's data without copying
  it. (RT#82826)
∗ Make a few tests more robust
* Created %meta_merge which follows v2 of CPAN Meta Spec
  - %meta_merge is used for generating metadata via
    ExtUtils::MakeMaker/CPAN::Meta