JBIDE-13434 BrowserSim: add taking screenshot ability

adding functionality
JBIDE-13434 BrowserSim: add taking screenshot ability

add copy image to clipboard fix for Linux
JBIDE-13434 BrowserSim: add taking screenshot ability

make screenshots folder configurable via preferences
JBIDE-13434 BrowserSim: add taking screenshot ability

menu simplification
JBIDE-13434 merge: BrowserSim: add taking screenshot ability