Editorial changes from comments by Hannes, Stefano, Saikat & Robert
- Added IP Reachability TLV in Prefix Descriptors
- Cleaned up code point inconsistencies
- Addressed FIXME (almost all - still need to decide if want to mandate the info inthe 64 bit IGP instance ID)
Merge branch 'master' of https://github.com/hannesgredler/draft-ietf-idr-ls-distribution