Apply formatting/style tweaks to comply with compile time diagnostics for g++ and clang++ (#686)

* Add compilation flags: -Wshadow -Weffc++ -pedantic -pedantic-errors
* Delete implicit copy & move constructors & assignment operators
  in classes with pointer data members.
* An exception to the above: Add default copy & move constructors &
  assignment operators for the Binary class.
* Convert boolean RegEx operators to binary operators.
* Initialize all members in all classes in ctors.
* Let default ctor delegate to the converting ctor in
  Binary and RegEx
* Don't change any tests except regex_test (as a result of the change
  to binary operators).

Note: https://bugzilla.redhat.com/show_bug.cgi?id=1544675 makes
-Weffc++ report a false positive in "include/yaml-cpp/node/impl.h".

src/nodeevents.h

@@ -26,13 +26,17 @@ class Node;
 class NodeEvents {
  public:
   explicit NodeEvents(const Node& node);
+  NodeEvents(const NodeEvents&) = delete;
+  NodeEvents(NodeEvents&&) = delete;
+  NodeEvents& operator=(const NodeEvents&) = delete;
+  NodeEvents& operator=(NodeEvents&&) = delete;
 
   void Emit(EventHandler& handler);
 
  private:
   class AliasManager {
    public:
-    AliasManager() : m_curAnchor(0) {}
+    AliasManager() : m_anchorByIdentity{}, m_curAnchor(0) {}
 
     void RegisterReference(const detail::node& node);
     anchor_t LookupAnchor(const detail::node& node) const;
@@ -59,6 +63,6 @@ class NodeEvents {
   typedef std::map<const detail::node_ref*, int> RefCount;
   RefCount m_refCount;
 };
-}
+}  // namespace YAML
 
 #endif  // NODE_NODEEVENTS_H_62B23520_7C8E_11DE_8A39_0800200C9A66