This section describes functions from file dld.ct.
[] = link(filename)
link("file.o") makes C-tela functions in "file.o" available
to Tela. "file.o" must be compiled from a C-tela file
(usually "file.ct").
Error codes:
1: Cannot initialize DLD
2: Cannot link-load file
3: Argument not string or char
4: Cannot find fninfo pointer
5: Internal inconsistency
6: Undefined symbols remain
7: main function returned error code
8: Could not dlclose the previous linkage
9: Too many dynamically linked modules
10: File not found