Add frames per second to Format struct

[EtiennePerot]

As per title. Currently there is no way to differentiate between Formats by frames-per-second.
YouTube supports 60fps video now, so it would be nice if the Format struct reflected that.

Bonus points for making the best format selector opt for higher-framerate, rather than only higher-resolution.

[BruceWangNo1]

I think the frame rate of a certain video is unavailable from the HTTP response until the video is actually downloaded locally to be examined. What do you think? @EtiennePerot

[EtiennePerot]

If that were true, how could the YouTube video player display "1080p60" or "720p60" (rather than "1080p"/"720p") in its video quality list, without itself having downloaded both of those video streams?

Example 60fps video if that helps: https://www.youtube.com/watch?v=MBRqu0YOH14

[BruceWangNo1]

As I found out, Format does include fps information in its "meta" field. However the maintainer decided not to include that in Format's main fields. I have added a method to struct Format, so you can access fps by Format.AccessMeta("fps"). The maintainer haven't merged my pull request yet, so check out my forked repository for more information. As for the mentioned bonus points you mentioned, I will probably start to work on it tomorrow. @EtiennePerot

[BruceWangNo1]

Bonus problem solved. Now you can use "best-fps" filter to get the best quality video with fps as the first priority. The maintainer has not merged my pull request yet. So check out my forked git repository. @EtiennePerot

[EtiennePerot]

Thank you! This is great. Link to pull request for the record: #48