Add CCS papers.

bibs/header.bib

@@ -198,6 +198,7 @@
 @STRING{ccs13       = ccs # ", Berlin, Germany" }
 @STRING{ccs14       = ccs # ", Scottsdale, Arizona" }
 @STRING{ccs15       = ccs # ", Boulder, Colorado" }
+@STRING{ccs16       = ccs # ", Vienna, Austria" }
 
 @STRING{dbpl        = {Database Programming Languages (DBPL)}}
 @STRING{dbpl05      = dbpl}
@@ -501,7 +502,7 @@
 @STRING{fossacs   = {International Confernece on Foundations of Software Science and Computation Structures {(FoSSaCS)}}}
 @STRING{fsttcs    = {Foundations of Software Technology and Theoretical Computer
                     Science (FSTTCS)} }
-@STRING{hcomp     = {Conference on Human Computation & Crowdsourcing (HCOMP)} }
+@STRING{hcomp     = {Conference on Human Computation \& Crowdsourcing (HCOMP)} }
 @STRING{hoots     = {Workshop on Higher Order Operational Techniques in
                     Semantics (HOOTS)} }
 @STRING{icalp     = {International Colloquium on Automata, Languages and