The code assumes static linking, and a single thread.  The editor de has
not been ported; the cord test program has.  The supplied WCC_MAKEFILE should
work for OS/2 but was not tested on.

Since we haven't figured out how to do partial linking or to build static
libraries, clients currently need to link against a long list of executables.

Notes:
* adding dynamic linking support seems easy, but was not done;
* adding thread support may be nontrivial, since we have not yet figured out
  how to look at another thread's registers;
* setjmp_test may yield overly optimistic results when compiled without
  optimization.