Default diff-printer to hide details (#103)

This new setting will make it print the difference between String()
output only.  This is more usable for developers in 99% of cases where
the difference can be seen.

Author: bboreham

test/diff.go

@@ -8,7 +8,9 @@ import (
 // Diff diffs two arbitrary data structures, giving human-readable output.
 func Diff(want, have interface{}) string {
 	config := spew.NewDefaultConfig()
-	config.ContinueOnMethod = true
+	// Set ContinueOnMethod to true if you cannot see a difference and
+	// want to look beyond the String() method
+	config.ContinueOnMethod = false
 	config.SortKeys = true
 	config.SpewKeys = true
 	text, _ := difflib.GetUnifiedDiffString(difflib.UnifiedDiff{