Variable normalization & Icon urls from search pages

I cleaned up some of the variable names for ratings and prices so that they matched across all of the data returned from market_bot, as well as adding the icon_url to the search/developer/leaderboard output.

I realize these aren't bugs and would cause issues with anyone using market_bot before these changes are merged. Never-the-less have a look and let me know what you think I'm willing to work with you and come to a common ground for these changes, until then I'll be working off my own branch.

Thanks!