Improve documentation in the header
Update the Readme
Use NS_ENUM rather than a straight enum
Modernise the implementation

Some minor changes to the documentation as well.
Add Mike Ash style constants for keys

Makes it easier for KVO.
Add a convenient reachabilityFlagsAsString method

Useful for logging, debugging.
Update spec file to point to version 0.2.0
Put guard arount WWAN SCNetworkStatusFlag

Only available on iOS.
Update the Readme with links to the example project.
Add note about the current maintainer

Also tidy up some silly typos. These changes are on top of the current
0.2.0 tag which is tracked by CocoaPods.