Merge remote-tracking branch 'upstream/master' into merge_upstream

Conflicts:
	backend/src/expert_searcher.hpp

	modified:   backend/src/expert_searcher.hpp
	modified:   backend/src/main.cpp
	modified:   backend/src/pminerimporter.cpp
	modified:   backend/src/search.cpp
	modified:   backend/src/search.hpp
Merge remote-tracking branch 'upstream/master' into merge_upstream
add InfluenceSearchByUser
add weibo apis
add weibo apis
fix a bug
make topics title
merge from ling he
add pn to pminer
Merge remote-tracking branch 'hui/merge_upstream'
fix influence hero unit