wireless_zh.bib: add xiong2012research
wireless.bib: add four refs on wireless v12n
add zhou's DWCS, and one about openflow eNodeB
add C-RAN, revise li2012toward
wireless.bib: add niu2012energy
wireless.bib: add openbts ref
wireless.bib: add gsm books, openbts manual
wireless.bib: add two standards, fix month
wireless.bib: add xu2013functionality
wireless.bib: fix missing comma