Add ability to specify list of supported platforms for a plugin

[ColinDuquesnoy]

Some plugin do not work on some specific platform (e.g. platform where there is no way to get proprietary codecs).

There would be a new field in the plugin metadata that is a list of supported platforms. The plugin manager would skip plugins if the current platform is not supported and the service wouldn't even show up in the services selection grid.

List of platforms:

• All: include all supported platforms
• Linux
• AppImage
• Windows
• OSX

Example of a plugin that works only on GNU/Linux but not from an AppImage:

author=Author name
author_website=Author email
icon=logo.svg
name=ServiceName
require_proprietary_codecs=true
supported_platforms:Linux
url=https://servicename.com/
version=1.0

And here is an example of plugin that works everywhere:

author=Author name
author_website=Author email
icon=logo.svg
name=ServiceName
require_proprietary_codecs=true
supported_platforms=All
url=https://servicename.com/
version=1.0

This could even should replace the require_proprietary_codecs key.

[ZeroDot1]

A very good feature it will help avoid confusion.
If there is the next update and new features have been added, I will do the German translation.

[ColinDuquesnoy]

Thank you. You will be notified by transifex when there are new strings to translate.

[ColinDuquesnoy]

We should also change the wizard to ask the developer of the plugin what platforms are supported.

[ZeroDot1]

Yes

[ZeroDot1]

The German translation is ready.

[ZeroDot1]

I have just tried it, is it correct that Linux is not specified although it was selected?

author=ZeroDot1
author_website=https://goo.gl/k3nTZn
icon=logo.svg
name=Test-Plug-In
supported_platforms=AppImage,OSX
url=https://colinduquesnoy.github.io/MellowPlayer/
version=1.0

[ColinDuquesnoy]

@ZeroDot1 No it is a bug. I fixed it. Thank you!