First 1.8 bugfixing release.

• Allow usage as a meson subproject
• Fix versioning
• Enhance configure script

First 1.8 bugfixing release.

1.8.1

Release 1.8.1

Release gst-transcoder 1.8

This is the first stable release of GstTranscoder.

First pre release in the 1.8 cycle

This is the first release ever but we follow GStreamer release versionning so that it is simpler when we get it merged into GStreamer itself.