Add 'mean' and 'reverse_mean' orderings for TermStatsFacet
Add 'mean' and 'reverse_mean' orderings for TermStatsFacet

HackLinux/pyes,haiwen/pyes,aparo/pyes,jayzeng/pyes,jayzeng/pyes,HackLinux/pyes,HackLinux/pyes,mavarick/pyes,aparo/pyes,Fiedzia/pyes,aparo/pyes,Fiedzia/pyes,haiwen/pyes,mavarick/pyes,haiwen/pyes,jayzeng/pyes,Fiedzia/pyes,mavarick/pyes