examples: enable linking both static and shared

examples: enable linking both static and shared

Since the DPDK build now includes both static and shared libraries, we need
a new way to enable building the examples using either method from the one
installation. To do this, we add in a default "shared" target, and a
separate "static" target which links in the DPDK static libraries. In both
cases, the final application name is symlinked to the last-built static or
shared target, with both binaries able to co-exist in the build directory.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Luca Boccassi <bluca@debian.org>