#11450: UPDATE: octave-2.9.9: Misc fixes including for #11181 and #11167

[David MacMahon]

The patch fixes #11167 and #11181, which were both caused by the  
problem outlined in #11167.

It also contains these changes:

1. Annotates doc-comment in glpk.m to indicate that the "memory used"  
value is not available for GPLK >= 4.15.

2. Modifies configure to use "set term aqua" instead of "set term  
x11" when checking whether gnuplot supports multiple windows because  
"set term x11" will fail if X11 is not running at the time.

3. Removes the dependency on curl. If anyone finds a real dependency  
on curl, it can be added back easily enough.

4. Moves the dependency on gnuplot up to depends_lib since gnuplot is  
used during configure.

5. Changes the dependency on gnuplot to be port:gnuplot since item 2  
above means that gnuplot needs to support aquaterm and requiring the  
gnuplot port rather than any old gnuplot binary seemed the safest way  
to ensure that.

Dave