Make a docker-in-docker dynamic binary and add RPM target

This change adds a new docker-in-docker dynamic binary make target which
builds a centos container for creating the dynamically linked binary.
To use it, you first must create the static binary and then call the
dind-dynbinary target.  You can call it like:

$ hack/make.sh binary dind-dynbinary rpm

This would then package the dynamic binary into the rpm after having
created it in the centos build container.  Unfortunately with this approach
you can't create the rpms and the debs with the same command.  They have to
be created separately otherwise the wrong version (static vs. dynamic) gets
packaged.

Various RPM fixes including:
  - Adding missing RPM dependencies.
  - Add sysconfig configuration files to the RPM.
  - Add an epoch to silence the fpm warning.
  - Remove unnecessary empty package.

Signed-off-by: Patrick Devine <patrick.devine@docker.com>
Signed-off-by: Chad Metcalf <chad@docker.com>

hack/make.sh

@@ -274,7 +274,7 @@ main() {
 	# We want this to fail if the bundles already exist and cannot be removed.
 	# This is to avoid mixing bundles from different versions of the code.
 	mkdir -p bundles
-	if [ -e "bundles/$VERSION" ]; then
+	if [ -e "bundles/$VERSION" ] && [ -z ${KEEPBUNDLE} ]; then
 		echo "bundles/$VERSION already exists. Removing."
 		rm -fr "bundles/$VERSION" && mkdir "bundles/$VERSION" || exit 1
 		echo