webgui: invoke TCanvas::Print() methods from web browser
webgui: invoke TCanvas::Print() methods from web browser

Required to produce PDF, PS, ROOT files. 
One need to disable Paint() protection in canvas - now it is protected
with Batch flag
karies/root,root-mirror/root,karies/root,root-mirror/root,olifre/root,olifre/root,karies/root,root-mirror/root,karies/root,root-mirror/root,karies/root,root-mirror/root,root-mirror/root,root-mirror/root,root-mirror/root,olifre/root,olifre/root,olifre/root,root-mirror/root,karies/root,olifre/root,root-mirror/root,karies/root,karies/root,karies/root,karies/root,karies/root,olifre/root,olifre/root,olifre/root,olifre/root,root-mirror/root,olifre/root