Fixes first three tests in about_constants.rb. I learned:

* when a variable is outside of a class (top level) it can be referenced by 
double colons.

* nested constants can be referenced by their complete paths.

[#65851854]
Fixes line 37 through the end of the file. I learned:

* Nested classes inherit constants from enclosing classes.

* When an inheritance is specified, the subclass inherits from the parent
class.

* The lexical scope takes precedence over the inheritance hierarchy, except
when it is defined in the class, in which case the class and subclass are 
lumped together and the inheritance passed to them.

[#65851854]
Merge pull request #13 from kkburr/65851854_about_constants_masters

about constants masters

[Delivers #65851854]