This shouldn't change behavior (or even object code) at all because
those assignments are all without effect. Removing that code removes
noise which helps working with code analysis tools.
This patch fixes many warnings from the beginning of the build up to
and including the depend stage. Nearly all warnings should be gone
even with -Wall.
Mostly missing headers, explicit parentheses and new prototypes.
Some Caveats:
* I haven't compile-tested the SVR4 getpty file, it might need another tweak
* There were operator precedence bugs in TermPrimCursor.c and TermPrimRender.c
(^ vs. !=). This might change behaviour, but at least I haven't experienced
any crashes ...
* This adds a little more dependencies for include ordering, but unless we
want to play the "headers that include headers that include headers..." game,
this is unavoidable.
