[RP] Resizable input window

[shawn]

...has been implemented. You can set the initial size in
conf.h. There's a catch: this size is the size of the input area not
including the prompt width. So if you put your screen width in, the
prompt won't be visible. There is of course a nice sick hack you can
do, since its a #define. To get the input window to fit the width of
the screen, set INPUT_WINDOW_SIZE to:

#define INPUT_WINDOW_SIZE (s->root_attr.width - prompt_width)

Gross eh?