Added Retrogaming.cloud grid provider

[wranders]

This aims to replace ConsoleGrid with Retrogaming.cloud as the grid image provider.
Has worked as intended on every ROM I've tested so far.

Two items to note, could be considered drawbacks associated with RG.C:

• Games have to be named exactly as the appear on the site. RG.C allows special characters that are not allowed in file paths, so a ROM name omitting a colon as a separator will fail to match (Eg.). This may be worked around by not using a literal search, but that seems to bring up many unrelated results.
• RG.C has an unspecified request rate limit. It appears to be around 150 per minute, but since 2 requests are required to retrieve the image URL, that number is half. Testing shows 70-80 ROM queries before the limit is triggered for an unspecified cool-down.

(Repost of #467 since HEAD changed.)

[technobone]

Please can you tell me where or how do I get a compiled version of ice with this pull request. Thanks

[wranders]

@technobone I don't have a compiled version. Only way at the moment is to clone and run from the shell. If you clone my latest branch, it includes this PR and the other that uses the new shortcut format.

[technobone]

Ok thankyou I'll take a look when I get chance. Thanks agin