Adding VHT Radiotap fields support
Parsing and UI representation for recently adopted VHT Radiotap fields for
802.11ac specification
http://www.radiotap.org/defined-fields/VHT
From me :
* Make checkAPIs happy
* Fix wrong last argument for some proto_tree_add_item
* Use proto_tree_add_item when it is possible
svn path=/trunk/; revision=44985