PSD article7:  implementation and tests of Vector2 class in C

Files:

vv.[ch]: a new "subclass of vector2" that overrides the print method
         to print more info - essentially overrideprint.c reimplemented
	 as a proper subclass

vector2.c:	changed intra-method calls inside normalize() to
		proper method calls - they were direct function calls.

simpletestvv.c: simple tests for vvs and vector2s, print the answers

testvv.c:	unit tests for vvs and vectors, answers encoded, only
                complains about failures

Rest of files unchanged from previous tarball:

overrideprint.c: an example which modifies an object's print() method on the fly

vector2.h:	class definition (no methods) of Vector2 class in C

testsupport.h:	unit testing support - prototypes and macros

testsupport.c:	unit testing support - functions

simpletestvector2.c: simple tests for vectors, print the answers

testvector2.c:	unit tests for vectors, answers encoded, only complains about failures
