libX: add new release / version info tags

libX: add new release / version info tags

This commit uses the $PACKAGE_VERSION automake variable to construct a
release and version info combination which sets the library name to be:

   libfoo-$(OVS_MAJOR_VERSION).so.$(OVS_MINOR_VERSION).0.$(OVS_MICRO_VERSION)

where formerly, it was always:

   libfoo.so.1.0.0

This allows releases of Open vSwitch libraries to reflect which specific
versions they came with, and sets up a psuedo ABI-versioning scheme.  In
this fashion, future releases of Open vSwitch could be installed
alongside older releases, allowing 3rd party utilities linked against
previous versions to continue to function.

ex:

$ ldd /path/to/utility
	linux-vdso.so.1 (0x00007ffe92cf6000)
	libopenvswitch-2.so.6 => /lib64/libopenvswitch-2.so.6 (0x00007f733b7a3000)
	libssl.so.10 => /lib64/libssl.so.10 (0x00007f733b530000)
...

Note the library name and version information.

Signed-off-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>