1) {About,Melp?} window: switch to green on black.
2) Assets window: scroll assets list on selected item update w/ <Cursor> or on deletion.
3) Canvas window: change default brush colours to [3, -1].
4) Canvas window: copy canvas cells given transparent cells from tools.
5) Canvas window: don't disable {re,un}do during object tool usage.
6) Canvas window: don't hide cursor during {re,un}do.
7) Canvas window: draw new cells using current brush background colour on resize.
8) Canvas window: fix memory leak on cell size updating.
9) Text tool: process [\r\n] in text pasted from clipboard.
assets/audio/roar{vap0r[1-8],viking[1-5]}.wav: added.
assets/text/README.txt: updated.
assets/tools/AnsiToMiRCART.py: added (for spoke.)
assets/tools/deploy-python.sh: updated.
