Except as otherwise specifically provided or indicated by the context, all words used in this Charter indicating the present tense shall not be limited to the time of the adoption of this Charter, but shall extend to and include the time of the happening of any event or requirement for which provision is made therein, either as a power, immunity, requirement, or prohibition. The chapter and section headings used in this Charter are for convenience only and shall not be considered to be a part of this Charter.