No more need to disable pthread for specific BSD's.

Pointer to current_log_name has to be changed even if the name is the
same, because the old one will be invalid/freed after reconfiguration.

When a BGP session was established by an outgoing connection with
Graceful Restart behavior negotiated, a pending incoming connection in
OpenSent state, and another incoming connection was received, then the
outgoing connection (and whole BGP session) was closed, but the old
incoming connection was just overwritten by the new one. That later
caused a crash when the hold timer from the old connection fired.

Jan Moskyto Matejka authored Nov 10, 2015 and Ondřej Zajíček committed Nov 24, 2015

Wanted netlink attributes are defined in a table, specifying
their size and neediness. Removing the long conditions that did the
validation before.

Also parsing IPv4 and IPv6 versions regardless on the IPV6 macro.

Patch from Pavel Tvrdik

If an interface address notification is received during device protocol
shutdown/restart, BIRD crashed.

Thanks to Wei Huang for the bugreport.

Jan Moskyto Matejka authored Nov 03, 2015 and Ondřej Zajíček committed Nov 11, 2015

Since 2.6.19, the netlink API defines RTA_TABLE routing attribute to
allow 32-bit routing table IDs. Using this attribute to index routing
tables at Linux, instead of 8-bit rtm_table field.

When a table is removed during reconfiguration, a reference was not
cleared in the old configuration, which breaks undo.

Symbol lookup by cf_find_symbol() not only did the lookup but also added
new void symbols allocated from cfg_mem linpool, which gets broken when
lookups are done outside of config parsing, which may lead to crashes
during reconfiguration.

The patch separates lookup-only cf_find_symbol() and config-modifying
cf_get_symbol(), while the later is called only during parsing. Also
new_config and cfg_mem global variables are NULLed outside of parsing.

I should check it after making some trivial changes. The original patch
from Alexander has it right.

If the number of sockets is too much for select(), we should at least
handle it with proper error messages and reject new sockets instead of
breaking the event loop.

Thanks to Alexander V. Chernikov for the patch.

The new RIP implementation fixes plenty of old bugs and also adds support
for many new features: ECMP support, link state support, BFD support,
configurable split horizon and more. Most options are now per-interface.

Thanks to Bernardo Figueiredo and Israel G. Lugo for the bugreport.

Thanks to Pavel Tvrdik for the bugfix

The patch adds suport for specifying route attributes together with
static routes, e.g.:

 route 10.1.1.0/24 via 10.0.0.1 { krt_advmss = 1200; ospf_metric1 = 100; };

Thanks to Thomas King for the bugreport.

Thanks to Christian Tacke for the original patch.

Thanks to Peter Hudec for noticing the problem.

Implements draft-ietf-idr-bgp-extended-messages-10, for now
undocumented and with temporary private capability number.