#26 Use readline in built in debugger

[Richard Quirk]

Tired of pressing the up arrow to get the previous
command and seeing "^[[A", I added basic readline to
the internal debugger. To see if the patch works, from
top level VisualBoyAdvance dir, check with:

zcat vba_readline.patch.gz | patch -p1 --dry-run

patch with:

zcat vba_readline.patch.gz | patch -p1

You will have to re-configure, since it uses a new flag
--enable-readline (defaults to no):

autoconf
./configure --enable-sdl --enable-readline

If readline library is not found (or not enabled), it
uses the old fgets approach. Changes in configure.in
and src/sdl/debugger.cpp

[Richard Quirk]

Enable readline in built in debugger. Pass --enable-readline to configure