Adds more methods to increase parity

The ability to retrieve all keys, to set a value ad retrieve it have been added

Fix issue with reading and writing config file

Fixes an issue with the implementation that made the XmlDocument fail when a config value is written to it

Adds default saving

This release adds overloads to the LoadFromXml and SaveToXml methods. Also, adds some stability improvements.

Initial Release

Support for creating, reading, writing and updating an XML config file.