New revision of OpenConfig BGP model.  Highlights of the changes:

Refactored multiprotocol module with explicit set of supported
AFI-SAFI combinations (using YANG identities) in a flattened list.
Focus was on common config with AFI-SAFI specific configuration
forthcoming.

Refactored policy module to work with a new general routing policy module
by augmenting BGP-specific policy options (matches and conditions).

Several new configuration items added to base bgp module.

The bgp-operational module is largely unchanged -- the next release
is expected to contain a significant update.
Initial version of general routing-policy module and associated
reusable types module for policy.  The routing policy module is
currently augmented by the bgp-policy module for bgp-specific
routing policy options.

The IGP policy items in this version of the module are limited to
generic items available in widely used protocols like IS-IS and OSPF.
Merge pull request #4 from openconfig/master

Update of OpenConfig BGP and routing policy models