Add Build Requirements from Makefile to spec file.

Add Build Requirements from Makefile to spec file.

JIRA: VPP-498

Changes to build to help with downstream distro builds
for Fedora, Centos and RHEL distros.
Add nasm, automake, libtool, byacc, bison and flex.
Remove libconfuse and dependencies.
Remove epel-release rpm and dependencies.
Add conditionals to work around Python 2 packaging
inconsistency in Fed 25.
Add numactl to rpm requirements.

Change-Id: Ia39f8b931dc87e42df56414d38662eb33c7a4ca7
Signed-off-by: Thomas F Herbert <therbert@redhat.com>