Updates the installer library to be static in the final image, saving the installers into Git and curl-ing the correct revision

docker-builders/Dockerfile.jbig2enc

@@ -29,7 +29,20 @@ RUN set -eux \
     && ./autogen.sh \
     && ./configure \
     && make \
+  && echo "Gathering package data" \
+    && dpkg-query -f '${Package;-40}${Version}\n' -W > ./pkg-list.txt \
   && echo "Cleaning up image" \
     && apt-get -y purge ${BUILD_PACKAGES} \
     && apt-get -y autoremove --purge \
-    && rm -rf /var/lib/apt/lists/*
+    && rm -rf /var/lib/apt/lists/* \
+  && echo "Moving files around" \
+    && mkdir build \
+    # Unlink a symlink that causes problems
+    && unlink ./src/.libs/libjbig2enc.la \
+    # Move what the link pointed to
+    && mv ./src/libjbig2enc.la ./build/ \
+    # Move the shared library .so files
+    && mv ./src/.libs/libjbig2enc* ./build/ \
+    # And move the cli binary
+    && mv ./src/jbig2 ./build/ \
+    && mv ./pkg-list.txt ./build/