Log Message:
Update to 0.99.17.

The most important change is in correcting handling of malformed data
in BGP sessions.

bgpd:
    fix handling of AS path data
    tighten bounds checking in RR ORF msg reader

ospfd:
    Only refresh external default route once.
    Make sure ospf_distribute_list_update_timer() eventually runs.
    Make sure all external routes are updated.

zebra:
    fix infinite loop when deleting an interface

ospf6d:
    Fix crash when '[no] ipv6 ospf6 advertise prefix-list' is in startup-config

isisd:
    change ISIS_METHOD to use C preprocessor

other:
    build: ignore mkinstalldirs and texinfo.tex
    build: Add QuaggaId to README.NetBSD
    build/extra: Enhance README.NetBSD make/gmake decision.
    git: add pointers to out-of-tree work
    git: add (generated) m4 files to .gitignore
    Update for git and emphasize asking for good reports.
    doc: fixed spelling in bgpd.texi