loci: fix byte swapping on OS X

The endian.h functions don't exist on OS X, so use the LOCI versions instead.
Also change the byte order macro used to one that's defined on both Linux and OS X.
Merge pull request #7 from floodlight/master

Pull from floodlight
adding instruction_id type for table feature prop types
adding of_instruction_id_to_object_id
adding instruction_id funcs
removing print statement
adding return statement
fixing bad arg
removing print statements
Merge into master from pull request #213:
Adding unpadded Instruction Ids for ofp_table_features_prop_instructions* (https://github.com/floodlight/loxigen/pull/213)
loci: add missing test for of_object_new_from_message

Also fix embarassing typos in test_of_object_new_from_message_preallocated.
loci: fix implicit truncation warning

The compiler complained about this in constant expressions.
Merge into master from pull request #203:
loci: fix byte swapping on OS X (https://github.com/floodlight/loxigen/pull/203)
Merge remote-tracking branch 'origin/master' into loci-parser

Conflicts:
	c_gen/c_type_maps.py
	c_gen/templates/of_type_maps.c