[fix] Resolve HTML filepath so backend.js can be run anywhere
[fix] Resolve HTML filepath so backend.js can be run anywhere

lzhengms/director,ks3dev/director,stonegithubs/director,sheldonzf/director,tanzhihang/director,vitalsource/director,pandoraui/director,flatiron/director,webx32/director,meleslilijing/director,lzhengms/director,andradedev/director,pocketjoso/director,GerHobbelt/director,ks3dev/director,fadeit/director,kiritoe/director,meleslilijing/director,vitalsource/director,pandoraui/director,andradedev/director,pocketjoso/director,cpg1111/director,mylikes/director,kiritoe/director,cpg1111/director,tanzhihang/director,mylikes/director,webx32/director,sheldonzf/director,stonegithubs/director,GerHobbelt/director,fadeit/director,maxogden/director