- added missing return to translation code.

- a bit of header cleanup.

* moved <zlib.h> and <bzlib.h> from files.h to files_decompress.cpp because they are no longer needed for defining the interface.
* added <functional> to the precompiled header

src/r_data/r_translate.cpp

@@ -743,6 +743,7 @@ bool FRemapTable::AddToTranslation(const char *range)
 	catch (CRecoverableError &err)
 	{
 		Printf("Error in translation '%s':\n%s\n", range, err.GetMessage());
+		return false;
 	}
 }