avoid writable string and deprecated implicit conversion warning

lib/poems/poemsobject.cpp

@@ -21,7 +21,7 @@
 
 POEMSObject::POEMSObject(){
   name = 0;
-  ChangeName("unnamed");
+  ChangeName((const char*)"unnamed");
   ID = -1;
 }
 
@@ -29,7 +29,7 @@ POEMSObject::~POEMSObject(){
   delete [] name;
 }
 
-void POEMSObject::ChangeName(char* newname){
+void POEMSObject::ChangeName(const char* newname){
   delete [] name;
   name = new char[strlen(newname)+1];
   strcpy(name,newname);

lib/poems/poemsobject.h

@@ -26,7 +26,7 @@ class POEMSObject {
 public: 
   POEMSObject();
   virtual ~POEMSObject();
-  void ChangeName(char* newname);
+  void ChangeName(const char* newname);
   char* GetName();
   int GetID();
   void SetID(int id);