- Make the autosegs read-only.

- Derive PClass from dobject.cpp. This has one major ramification: Since the PClass
  is not allocated until runtime, you cannot initialize any static/global data
  structures with pointers to PClasses using RUNTIME_CLASS. Attempting to do so
  will just initialize with a NULL pointer. Instead, you can initialize using
  the address of the pointer returned by RUNTIME_CLASS and dereference that. By
  the time you have an opportunity to dereference it, it will no longer be NULL.
- Sync CmakeLists.txt.
- Random fixes for problems GCC spotted.

SVN r1852 (scripting)

src/p_map.cpp

@@ -4906,7 +4906,7 @@ msecnode_t *P_AddSecnode (sector_t *s, AActor *thing, msecnode_t *nextnode)
 
 	if (s == 0)
 	{
-		I_FatalError ("AddSecnode of 0 for %s\n", thing->_StaticType.TypeName.GetChars());
+		I_FatalError ("AddSecnode of 0 for %s\n", thing->GetClass()->TypeName.GetChars());
 	}
 
 	node = nextnode;