add webgl rendering to firefox

Signed-off-by: Jessica Frazelle <princess@docker.com>

iceweasel/Dockerfile

@@ -1,10 +1,13 @@
-FROM debian:jessie
+FROM debian:sid
 MAINTAINER Jessica Frazelle <jess@docker.com>
 
-RUN sed -i.bak 's/jessie main/jessie main contrib/g' /etc/apt/sources.list && \
+RUN sed -i.bak 's/sid main/sid main contrib/g' /etc/apt/sources.list && \
     apt-get update && apt-get install -y \
     flashplugin-nonfree \
+    hicolor-icon-theme \
     iceweasel \
+    libgl1-mesa-dri \
+    libgl1-mesa-glx \
     --no-install-recommends
 
 COPY local.conf /etc/fonts/local.conf