fix io._detect_filename to work with IDEs
fix io._detect_filename to work with IDEs

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