added two new print tests (for \b and \r characters)

valid/IO/print/print-backspace.wacc

+# simple print statement off a string with a backspace character
+
+# Output:
+# Hell World!
+
+# Program:
+
+begin  
+  print "Hello\b World!\n"
+end

valid/IO/print/print-carridge-return.wacc

+# simple print statement off a string with a carridge-return character
+
+# Output:
+#  World!
+
+# Program:
+
+begin
+  print "Hello \r World!\n"
+end