A terminal based vcd viewer
q: quit
a: select window to the left of currently selected window
d: select window to the right of currently selected window
---- Explorer Window --------------------------
w: move selection up
s: move selection down
e: expand/collapse (used in Explorer window)
enter: add signal to Signals window
---- Signals Window --------------------------
w: move selection up
s: move selection down
backspace: remove signal from Signals Window
---- Monitor Window --------------------------
i: zoom in
k: zoom out
j: pan left
l: pan right