psTrace fails to handle new file pointers correctly

[eugene]

There are two related problems here.

1) traceFP is defined static and set initially to NULL. Throughout the code,
wherever there is a use of traceFP, it it tested, and if NULL, printf statements
are used, otherwise fprintf statements are used. This leads to both code that
is hard to read, and also possible inconsistencies depending on the device

2) the function psTraceSetDestination was leaving the last value of traceFP open
and inaccesible. It was not closing it, nor was it testing for it to be closeable.

I have fixed both of these issues, and am attaching the updated code

[eugene]

psTrace.c with fixes for psTraceSetDestination, NULL tests

[eugene]

psTrace.h to match psTrace.c

[robert.desonia@…]

files taken pretty much as is and folded into CVS.

[robert.desonia@…]

N.B., the only change was to make the default destination stdout, not stderr, as
required by the SDRS.