document.py: when wrapping callbacks to set curdoc, return the callback's result
document.py: when wrapping callbacks to set curdoc, return the callback's result

This is needed for example if the callback is async and it returns
a Future.

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