This adds a lot more unit tests for Common::INIFile and fixes some small
problems identified during their creation. Specifically:
* addSection() did not check the validity of the section name, which meant it
was possible to create a section that could not then be operated on by the
other functions (which all check validity)
* If allowNonEnglishCharacters was set, it was possible to create a key or
section name starting with '[' or '#', or including a carriage return. This
would not read back in correctly.
* Blank section and key names were considered valid, but neither would be
read back in correctly.
* The struct documentation did not mention whitespcae handling or that comments
include the '#' and carriage return.
