(gdb-same-frame): New option.

(gdb-same-frame): New option.
(gud-old-arrow, gdb-frame-begin, gdb-printing): New variables.
(gdb-init-1): Initialise them.
(gdb-starting): Reset gdb-printing
(gdb-starting): Save value of gud-overlay-arrow-position.
(gdb-frame-begin): Set gdb-frame-begin, gdb-printing.
(gdb-stopped): Don't look for source if calling procedure e.g "p a ()".
Use gdb-*-gdb-buffer conditionally on gdb-same-frame.
(gdb-frame-gdb-buffer): Keep menu bar, tool bar for GUD buffer.