with an invalid path, as in getprop("/sim/model/737") or x.getNode("f:1").
Forward sg's error message to the Nasal runtime error function instead, so
you get something like:
Nasal runtime error: name must begin with alpha or '_'
at /home/m/fgfs/Base.local/Nasal/props.nas, line 30
Unfortunately, the location points to the line where the ghost wrapper
sits, rather than the offending script line.
scripts) to create dialogs at runtime. Augment "dialog-close" to take
a name argument, allowing code other than PUI callbacks to close
dialogs.
The changes to the GUI directory to enable this are actually minor,
basically amounting to using SGPropertyNode_ptr reference counting
(the GUI subsystem no longer "controls" the dialog property trees, so
it can't delete them).
