Every GTK function used by a script must be described here. First the name of
the function itself must be mentioned, after that a callback signal if applicable. The real
names for the GTK callback signals must be used here. Then the type of the returnvalue
must be specified. The type can be one of the following:
NONE, WIDGET, BOOL, STRING, LONG or FLOAT. After that, it must be clear how many
arguments the GTK function needs. Finally, the type of each indivdual argument must be declared.
The type of the arguments can be one of the following: NULL, WIDGET, STRING, LONG or FLOAT.
Example:
GTK_LIB_FUNCTION = gtk_window_new, delete-event, WIDGET, 1, LONG