Generalized signal handling

Dockerfile

@@ -12,6 +12,8 @@ RUN apt-get install -y wget
 RUN apt-get install -y git make gcc
 RUN apt-get install -y icewm
 RUN apt-get install -y x11-apps
+RUN apt-get install -y bc
+RUN apt-get install -y net-tools socat python3-numpy
 
 FROM base as build
 ADD https://github.com/TurboVNC/turbovnc/releases/download/3.1.1/turbovnc_3.1.1_amd64.deb /tmp/
@@ -24,9 +26,6 @@ RUN dpkg -i turbovnc_3.1.1_amd64.deb
 WORKDIR "/tmp/websockify"
 RUN make -j4
 
-# develop only
-RUN apt-get install -y net-tools socat python3-numpy
-
 ENV PATH=$PATH:/opt/TurboVNC/bin
 RUN	mkdir ~/.vnc/
 RUN	echo $PASSWORD | vncpasswd -f > ~/.vnc/passwd