param: refactor BlockParam classes

- make the selected parameter a template argument. This
  enables type-checking at compile-time.
- move things to src/platforms.
  This provides consistent includes with ModuleBase
- add ModuleParams base class (replaces Block & SuperBlock)
- drop the Block* prefix from the class names

src/lib/controllib/block/Block.cpp

@@ -96,6 +96,8 @@ void Block::updateParams()
 		param->update();
 		param = param->getSibling();
 	}
+
+	updateParamsSubclass();
 }
 
 void Block::updateSubscriptions()

src/lib/controllib/block/Block.hpp

@@ -84,6 +84,8 @@ public:
 
 protected:
 
+	virtual void updateParamsSubclass() {}
+
 	SuperBlock *getParent() { return _parent; }
 	List<uORB::SubscriptionNode *> &getSubscriptions() { return _subscriptions; }
 	List<uORB::PublicationNode *> &getPublications() { return _publications; }