Added ZString constructor for assignment on definition.

MString.cpp

@@ -37,6 +37,12 @@ namespace coreutils {
       memcpy(this->data, data, length);
       cursor = this->data;
    }
+
+   MString::MString(ZString zstring) {
+      setSize(zstring.getLength());
+      memcpy(data, zstring.getData(), zstring.getLength());
+      cursor = data;      
+   }   
    
    MString::MString(const MString &mstring) {
       setSize(mstring.length);