add tests for new legend sorting attributes
add tests for new legend sorting attributes

aavanian/bokeh,justacec/bokeh,philippjfr/bokeh,aavanian/bokeh,schoolie/bokeh,bokeh/bokeh,aiguofer/bokeh,rs2/bokeh,Karel-van-de-Plassche/bokeh,azjps/bokeh,DuCorey/bokeh,ptitjano/bokeh,stonebig/bokeh,philippjfr/bokeh,timsnyder/bokeh,clairetang6/bokeh,ptitjano/bokeh,schoolie/bokeh,draperjames/bokeh,rs2/bokeh,mindriot101/bokeh,ptitjano/bokeh,philippjfr/bokeh,bokeh/bokeh,Karel-van-de-Plassche/bokeh,ericmjl/bokeh,draperjames/bokeh,phobson/bokeh,percyfal/bokeh,percyfal/bokeh,ericmjl/bokeh,schoolie/bokeh,mindriot101/bokeh,clairetang6/bokeh,ericmjl/bokeh,phobson/bokeh,justacec/bokeh,rs2/bokeh,philippjfr/bokeh,DuCorey/bokeh,jakirkham/bokeh,justacec/bokeh,azjps/bokeh,clairetang6/bokeh,bokeh/bokeh,azjps/bokeh,justacec/bokeh,dennisobrien/bokeh,dennisobrien/bokeh,aiguofer/bokeh,timsnyder/bokeh,philippjfr/bokeh,draperjames/bokeh,schoolie/bokeh,draperjames/bokeh,rs2/bokeh,bokeh/bokeh,stonebig/bokeh,dennisobrien/bokeh,azjps/bokeh,stonebig/bokeh,percyfal/bokeh,quasiben/bokeh,quasiben/bokeh,aavanian/bokeh,phobson/bokeh,aavanian/bokeh,timsnyder/bokeh,Karel-van-de-Plassche/bokeh,DuCorey/bokeh,ptitjano/bokeh,jakirkham/bokeh,draperjames/bokeh,quasiben/bokeh,dennisobrien/bokeh,Karel-van-de-Plassche/bokeh,mindriot101/bokeh,stonebig/bokeh,percyfal/bokeh,mindriot101/bokeh,jakirkham/bokeh,Karel-van-de-Plassche/bokeh,jakirkham/bokeh,timsnyder/bokeh,timsnyder/bokeh,schoolie/bokeh,phobson/bokeh,clairetang6/bokeh,percyfal/bokeh,phobson/bokeh,aiguofer/bokeh,ptitjano/bokeh,bokeh/bokeh,aavanian/bokeh,aiguofer/bokeh,aiguofer/bokeh,DuCorey/bokeh,jakirkham/bokeh,dennisobrien/bokeh,ericmjl/bokeh,azjps/bokeh,rs2/bokeh,ericmjl/bokeh,DuCorey/bokeh