ISteamWebAPIUtil.GetSupportedAPIList() package parsing mechanism

[michaeljohnbarr]

Each interface has methods with a unique <method_version> keyword argument. If we retrieve the latest version of each method as reported by ISteamWebAPIUtil.GetSupportedAPIList() and compare them to our methods, we can nearly guarantee that we can keep our package updated with the latest method versions. Other benefits are listed below.

• Make sure the <method_version> keyword argument has the latest/correct default version
• Make sure that we have all available interfaces exposed within the package
• Make sure that we have all methods exposed underneath the interfaces
• Implement as a unittest.TestCase (as outlined in Issue unittest.TestCase Suites are needed for all Interfaces/Methods #4)