Resolve "Add time_tolerance field in Frame and remove PackKeyFrame"

Closes #420 (closed)

include/core/processor/processor_base.h

@@ -126,7 +126,7 @@ public:
     /**\brief Add a element to the buffer
     *
     */
-    void add(const TimeStamp& _time_stamp, const T& _element); //const double& _time_tolerance);
+    void emplace(const TimeStamp& _time_stamp, const T& _element); //const double& _time_tolerance);
 
     /** \brief returns the container with elements of the buffer
     *
@@ -558,7 +558,7 @@ T Buffer<T>::selectLast()
 }
 
 template <typename T>
-void Buffer<T>::add(const TimeStamp& _time_stamp, const T& _element)
+void Buffer<T>::emplace(const TimeStamp& _time_stamp, const T& _element)
 {
     container_.emplace(_time_stamp, _element);
 }