Feature - merge command

- Merged patch that implements the first milestone of the merge
  feature.  Thanks to Johannes Schlatow.

src/Att.cpp

@@ -154,6 +154,14 @@ Att& Att::operator= (const Att& other)
   return *this;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+bool Att::operator== (const Att& other) const
+{
+  return mName  == other.mName &&
+         mMod   == other.mMod  &&
+         mValue == other.mValue;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 Att::~Att ()
 {