Well, a couple of days have gone by, so I assume that items (a) and (b)

Well, a couple of days have gone by, so I assume that items (a) and (b)
in the freeglut_cursor.c file's "Open issues" comment are now satisfactor-
ily closed.

I also partially implemented some error-checking, using my limited
understanding of how Xlib users are supposed to do this.  (No one commented
about the lack of error-checking, pro or con.  Perhaps someone will care to
comment now?)

At present, it just will print out a warning, via fgWarning().  In part
because I'm not sure what is best to do, and in part because failure to
set the cursor type is probably not a fatal problem.

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@327 7f0cb862-5218-0410-a997-914c9d46530a