Add vessel entity

entities/vessel_entity.cpp

@@ -0,0 +1,24 @@
+#include "vessel_entity.h"
+
+
+unsigned long long vessel_entity::__global_id = 0;
+
+vessel_entity::vessel_entity(const dpoint_entity &harbor, unsigned int capacity) : _harbor(harbor), _capacity(capacity) {
+    this->_id = ++vessel_entity::__global_id;
+}
+
+unsigned long long vessel_entity::id() {
+    return this->_id;
+}
+
+const dpoint_entity vessel_entity::harbor() {
+    return this->_harbor;
+}
+
+unsigned int vessel_entity::capacity() {
+    return this->_capacity;
+}
+
+const QVector<cargo_entity> vessel_entity::cargo() {
+    return this->_cargo;
+}