Add support for IPlayerService Web API service operations

[Yeggstry]

Since the XML feed is now deprecated, This service has been provided to provide missing functionality around player game data.

The operations available are:

GetRecentlyPlayedGames (v1)
GetOwnedGames (v1)

[Yeggstry]

As mentioned in #195, the GetOwnedGames operation has a flag called include_appinfo, and this doesn't seem to be working at the moment. It looks like it should provide the name and logos of the app, but by including include_appifo=true I get the same result as when I don't include the parameter.

[koraktor]

Try include_appinfo=1. Another evidence of Valve's poor API design. 😒

What's not working is the appids_filter described here. See my "bug report" here.

[Yeggstry]

Ah yes, thanks. The joys of a boolean being either 0 or 1, or true or false :)

I did try using the appids_filter as well, however didn't have much luck. As far as I can see this is the first service in the API to use this functionality.