Runtime: work around 1s delay added when using twisted reactor's callLater.

Since wxPython4, using wxReactor from non-main thread was producing
exceptions in wxWidget's C++ code. Then reactor.run() was called from
main thread, and runtime's worker was delegating calls to reactor
with callLater(0, callable).

While this worked perfectly with wxReactor, it did introduce an unexplained
1 second delay to each worker call when using nomal linux reactors
(i.e. without wxPython). As a workaround reactor runs in a thread when using
twisted without wxPython

#!/bin/sh

INKSCAPE=inkscape

for fname in `ls *.svg`; do
    for i in `cat $fname |grep -o -e '%%[^%]*%%'|sed 's/%//g'` 
    do
        if [ $i.png -nt $fname ]; then
 	    echo "Skip $i"
        else
	    rm  -f $i.png
	    echo "$INKSCAPE" $fname -z -e $i.png -i $i
	    "$INKSCAPE" $fname -z -e $i.png -i $i
        fi
    done
done

cp ico024.png brz.png
convert -compress none ico???.png brz.ico
rm -f ico???.png


convert -compress none poeico*.png poe.ico
rm -f poeico*.png