WIP: First attempt to approach the issue bob.bio.base#106

In this issue I'm:

1. Removing the loading and saving functions via HDF5 in the C++ and in the python API (not sure if it's really necessary to remove from the C++ level)

2. Implemented the methods to_dict and from_dict for the activation functions

3. Test cases

Maybe I would need a bob.nightlies just for this

bob/learn/activation/cpp/ActivationRegistry.cpp

@@ -16,11 +16,6 @@ boost::shared_ptr<bob::learn::activation::ActivationRegistry> bob::learn::activa
   return s_instance;
 }
 
-boost::shared_ptr<bob::learn::activation::Activation> bob::learn::activation::load_activation(bob::io::base::HDF5File& f) {
-  auto make = ActivationRegistry::instance()->find(f.read<std::string>("id"));
-  return make(f);
-}
-
 boost::shared_ptr<bob::learn::activation::Activation> bob::learn::activation::make_deprecated_activation(uint32_t e) {
   switch(e) {
     case 0:
@@ -99,11 +94,11 @@ bob::learn::activation::activation_factory_t bob::learn::activation::ActivationR
  */
 template <typename T> struct register_activation {
 
-  static boost::shared_ptr<bob::learn::activation::Activation> factory (bob::io::base::HDF5File& f) {
+  static boost::shared_ptr<bob::learn::activation::Activation> factory () {
     auto retval = boost::make_shared<T>();
-    retval->load(f);
     return retval;
   }
+ 
 
   register_activation() {
     T obj;