For discussion of the package internals, see hackguide.html in the misc
directory.

Here are some -D options you might need to compile with.
The 'configure' script gets most other definitions right automatically.
  
-DHAVE_SIGACTION	if the sigaction function is present

-DHAVE_USLEEP		if the usleep function is present

-DSVR4_ACTION		if (e.g., svr4) you need _POSIX_SOURCE to have sigaction

-DSVR4_TERMIO		if (e.g., svr4) you need _POSIX_SOURCE to have termio

-DOPT_MVCUR		if you want mvcur() to cost its actions or you have a
			terminal that doesn't have direct cursor addressing.

There are several problems with strict POSIX systems so extra flags
or #define's may be needed.
