removed operator= and copy ctor from classes where they only duplicated the behaviour of the default implementations that C++ generates automatically

src/blackmisc/avaltitude.cpp

@@ -22,17 +22,6 @@ QString CAltitude::convertToQString(bool /* i18n */) const
     return s.append(this->m_msl ? " MSL" : " AGL");
 }
 
-/*
- * Assigment
- */
-CAltitude &CAltitude::operator =(const CAltitude &other)
-{
-    if (this == &other) return *this;
-    CLength::operator = (other);
-    this->m_msl = other.m_msl;
-    return *this;
-}
-
 /*
  * Equal?
  */