loci: generate list accessors with a template

Still uses the legacy code to figure out which lists to generate.
loci: generate lists from the IR
loci: replace of_object_wire_init in list accessors

The of_object_t was already initialized in the list_first accessor. Most of the
work done by the init call in of_object_init is redundant, and as an indirect
call from a central function it is likely to be mispredicted.
loci: factor out class metadata generation

The parsing code also needs this at compile time.
loci: replace indirect wire_length_get calls

All objects of the same inheritance tree use the same wire length accessors. We
know what inheritance tree we're working with, so generate a direct call.
loci: remove of_object_fixed_len lookup from list accessors

This can be done once inside the base class init function during the 'first'
operation.
loci: remove dead code
add bsn_log extension

This provides a mechanism for either the controller or switch to request the
other side to output a log message, subject to the configured loglevel. This is
useful for log (and OpenFlow pcap) correlation.
Merge into master from pull request #289:
Fix type of of_flow_stats_entry.flags, smaller fixes to Java (https://github.com/floodlight/loxigen/pull/289)
bsn_log: add a comment about the string format
Merge remote-tracking branch 'origin/master' into codegen-list
loci: fix merge with of_object_attach changes

We don't want to do the wire buffer grow check when iterating over a list.
loci: simplify list type extraction
Merge into master from pull request #284:
Convert list accessors to templates and optimize (https://github.com/floodlight/loxigen/pull/284)
Merge into master from pull request #288:
add bsn_log extension (https://github.com/floodlight/loxigen/pull/288)
Add vrf counter request/reply.

Add OFP_BSN_VLAN_ALL constant to request counters for all vlans.
OFP_BSN_VRF_ALL should be 32 bits in length.
Change wire_type of VRF_ALL to uint32_t.
Merge into master from pull request #291:
Add vrf counter request/reply. (https://github.com/floodlight/loxigen/pull/291)
java_gen: make of_bsn_log a string