Creates LineByLineObject class

Mobiles, Objects, and Rooms are all parsed one line at a time, comparing
the expected line structure with the actual line structure (keeping
track of expectations via an array of symbols, an index variable, and
a case structure.)

The Mobile, Object, and Room objects (only Mobile is written atm) keeps
its array of lines in self.LINES, as well as a lot of methods named
"parse_#{self.LINES[n]}". LineByLineObject uses the index variable to
find the expected line, then calls send("parse_#{self.class.LINES[i]}").