build.sh: improve plugins and features copy to reduce warning messages.
build.sh: improve plugins and features copy to reduce warning messages.

ControlSystemStudio/org.csstudio.iter,css-iter/org.csstudio.iter,ControlSystemStudio/org.csstudio.iter,css-iter/org.csstudio.iter,ControlSystemStudio/org.csstudio.iter,ControlSystemStudio/org.csstudio.iter,css-iter/org.csstudio.iter,ControlSystemStudio/org.csstudio.iter,css-iter/org.csstudio.iter,css-iter/org.csstudio.iter,css-iter/org.csstudio.iter,ControlSystemStudio/org.csstudio.iter,css-iter/org.csstudio.iter,ControlSystemStudio/org.csstudio.iter,css-iter/org.csstudio.iter,ControlSystemStudio/org.csstudio.iter