This fixes the problem that many terminals require command line
parameters to be passed as command line parameters to the terminal
command. The old code would pass the whole gdb command including
all it's arguments (whatever replaces %s) as a single argument,
regardless of whether there are quotes around the %s or not.
Now those arguments are passed as separate arguments if there
are no quotes around the %s.
Updated documentation with an example on how to open a gdb terminal
on a different machines X display.
b5b6d3f85c