OperatingSystem: Better path separator explanation.
OperatingSystem: Better path separator explanation.

Earlier didn't explain why backslash is problematic. Fixes #1929.

moto-timo/robotframework,suvarnaraju/robotframework,yonglehou/robotframework,yonglehou/robotframework,stasiek/robotframework,nmrao/robotframework,rwarren14/robotframework,wojciechtanski/robotframework,ashishdeshpande/robotframework,synsun/robotframework,edbrannin/robotframework,moto-timo/robotframework,ashishdeshpande/robotframework,moto-timo/robotframework,SivagnanamCiena/robotframework,JackNokia/robotframework,snyderr/robotframework,kurtdawg24/robotframework,suvarnaraju/robotframework,un33k/robotframework,userzimmermann/robotframework,jorik041/robotframework,ashishdeshpande/robotframework,stasiek/robotframework,moto-timo/robotframework,rwarren14/robotframework,kyle1986/robortframe,ChrisHirsch/robotframework,Colorfulstan/robotframework,dkentw/robotframework,wojciechtanski/robotframework,fingeronthebutton/robotframework,fingeronthebutton/robotframework,dkentw/robotframework,nmrao/robotframework,synsun/robotframework,robotframework/robotframework,alexandrul-ci/robotframework,synsun/robotframework,dkentw/robotframework,joongh/robotframework,fingeronthebutton/robotframework,SivagnanamCiena/robotframework,suvarnaraju/robotframework,alexandrul-ci/robotframework,xiaokeng/robotframework,nmrao/robotframework,alexandrul-ci/robotframework,userzimmermann/robotframework,joongh/robotframework,SivagnanamCiena/robotframework,nmrao/robotframework,synsun/robotframework,wojciechtanski/robotframework,dkentw/robotframework,wojciechtanski/robotframework,un33k/robotframework,SivagnanamCiena/robotframework,kurtdawg24/robotframework,ashishdeshpande/robotframework,alexandrul-ci/robotframework,ChrisHirsch/robotframework,kurtdawg24/robotframework,fingeronthebutton/robotframework,xiaokeng/robotframework,snyderr/robotframework,userzimmermann/robotframework,kyle1986/robortframe,ChrisHirsch/robotframework,robotframework/robotframework,alexandrul-ci/robotframework,un33k/robotframework,yahman72/robotframework,edbrannin/robotframework,Colorfulstan/robotframework,JackNokia/robotframework,snyderr/robotframework,rwarren14/robotframework,joongh/robotframework,userzimmermann/robotframework,wojciechtanski/robotframework,JackNokia/robotframework,snyderr/robotframework,jaloren/robotframework,kyle1986/robortframe,ashishdeshpande/robotframework,Colorfulstan/robotframework,ChrisHirsch/robotframework,Colorfulstan/robotframework,jaloren/robotframework,ChrisHirsch/robotframework,HelioGuilherme66/robotframework,yonglehou/robotframework,snyderr/robotframework,jaloren/robotframework,suvarnaraju/robotframework,jaloren/robotframework,nmrao/robotframework,fingeronthebutton/robotframework,yonglehou/robotframework,JackNokia/robotframework,joongh/robotframework,edbrannin/robotframework,HelioGuilherme66/robotframework,dkentw/robotframework,edbrannin/robotframework,xiaokeng/robotframework,kurtdawg24/robotframework,moto-timo/robotframework,stasiek/robotframework,yahman72/robotframework,rwarren14/robotframework,jorik041/robotframework,Colorfulstan/robotframework,edbrannin/robotframework,un33k/robotframework,suvarnaraju/robotframework,kurtdawg24/robotframework,jaloren/robotframework,kyle1986/robortframe,stasiek/robotframework,xiaokeng/robotframework,yahman72/robotframework,un33k/robotframework,jorik041/robotframework,xiaokeng/robotframework,SivagnanamCiena/robotframework,synsun/robotframework,rwarren14/robotframework,joongh/robotframework,HelioGuilherme66/robotframework,jorik041/robotframework,yahman72/robotframework,jorik041/robotframework,yonglehou/robotframework,yahman72/robotframework,userzimmermann/robotframework,JackNokia/robotframework,stasiek/robotframework,kyle1986/robortframe,robotframework/robotframework