Platform detection disabled by default

Some users are confused by the platform detection. For example, if they have the Cocos2D docset and ALT+Click on something Cocos2D, the plugin causes Dash to ignore the Cocos2D docset. This is even worse considering that third-party docsets are becoming quite popular (e.g. cocoadocs.org), as all other docsets except iOS or OS X would be ignored.

While platform detection is useful sometimes, I think it's best to avoid confusion and have it disabled by default, at least until there's a way of getting it to work reliably.