add Rev support for clado state freqs
added csf to example bg .Rev files
update bg tutorial, add bg useTail support
Merge branch 'development' of github.com:revbayes/revbayes into development
bg tutorial change
Merge branch 'development' of github.com:revbayes/revbayes into development
Merge branch 'development' of github.com:revbayes/revbayes into development
Merge branch 'development' of github.com:revbayes/revbayes into development
updated readme
bg char history updates
Merge branch 'development' of github.com:revbayes/revbayes into development