Defined the ErrorManager class

Defined all the components of the ErrorManager java class,
attributes: errorManager (String), gotError(boolean), lines (String[])
methods: ErrorManager(Filer fil) [Constructor], fileNotComplete (void),
scoreOver10 (void), lineSizeExeeded (void), noNumbers (void),
getErrorMessage (String), getErrorAdvisor (boolean), isNotANumber(char
c) (boolean)