Revive boostbook.py tests, working around BoostBook dislike of classes

outside of any namespaces.


[SVN r33636]

v2/test/boostbook/a.hpp

@@ -1,7 +1,12 @@
 
+// Seems like Boostbook does like classes outside of namespaces,
+// and won't generate anything for them.
+namespace boost {
+
 /// A class
 class A {
 public:
     /// A constructor
     A();    
 };
+}