Merge pull request #1 from floodlight/master

Syncing with floodligh/loxigen
Merge pull request #3 from floodlight/master

Keeping master up to date
loci: expose group-mod subtypes

I wanted to use the real IR inside loci to begin rewriting the wire type mess,
but hiding the group mod subclasses was getting in the way.
Peeker function for reading subclass discriminator
Handling virtual classes
One more enum
Merge into master from pull request #149:
add bsn_counter request reply (https://github.com/floodlight/loxigen/pull/149)
Merge into master from pull request #150:
loci: expose group-mod subtypes (https://github.com/floodlight/loxigen/pull/150)
loxi_ir: automatically generate action/instruction ID classes

These are used in the table features multipart messages.
py_gen: move ID classes into their own modules
loci: use ID classes from the IR

Instead of building them itself.
java_gen: support action and instruction IDs
Merge into master from pull request #151:
automatically generate action/instruction ID classes (https://github.com/floodlight/loxigen/pull/151)
Doing virtual classes the right way
Adding definition of info variable
Doing ofclass_dissector the right way
Simplifying reader functions
Merge into master from pull request #152:
Handling virtual classes in wireshark_gen (https://github.com/floodlight/loxigen/pull/152)
loxi_ir: add convenience property OFClass.has_type_members
loci: use IR in class_is_virtual