ConfigurationSettings.AppSettings: Write and read configuration files like in .NET

This class can be used to read and write application XML configuration files.

It emulates the behavior of the ConfigurationSettings.AppSettings class of the .NET framework.

It can create new configuration files. If a configuration file with a given path do not exist, it creates the file.

It provides functions for setting or getting the configuration value for a given key. If a key does not exist, the class adds it to the configuration file XML document before saving it.