plugin.gaminglive: basic support for gaming live
plugin.gaminglive: accept new alpha.gaminglive.tv url
plugins.gaminglive: Make use of the validation API.

Also convert line endings from dos to unix.
Update CHANGELOG.rst.
docs: Update plugin matrix.
Update AUTHORS.
Merge pull request #468 from chhe/gaming-live

Added plugin for gaminglive.tv.