Add a list of HLS executable file paths in settings

[berberman]

Although it is convenient for most of us, sometimes it can be noisy. I need switch hls between few versions (dynamic linked / static linked), and hls may not appear in PATH. Opening a project, I will find that the plugin has already started downloading it, before I set the path to hls executable manually, so I have to deleted the downloaded binaries to keep it clean, even if those binaries will not make any difference in runtime.

[jneira]

@berberman thanks for the suggestion, it makes totally sense. Fortunately the download is configurable in master, only left publish the extension.
(the pr closed #294, duplicate of this one)

[berberman]

Perhaps maintaining a list of hls executables' paths for switching in the settings will be nice. 😉

[jneira]

That would be nice too, please change the title of the issue then (or open a new one, as you wish)

[fendor]

Not relevant any more, if still a problem, please open a new issue with a new description.