Ensures a section with the specified name exists, adding a new one if it does not yet exist.
@param sectionName the name of the section to ensure existence
@return the section created if it did not yet exist, or the existing IniSection that already existed.
Ensures a section with the specified name exists, adding a new one if it does not yet exist.
@param sectionName the name of the section to ensure existence @return the section created if it did not yet exist, or the existing IniSection that already existed.