add freehand drawing branch
add ignore file
add ignore file
add ignore file
create canvas when slide change(it'll be modified to create when user open this function)
add icons
merge speaker.html from master
add icon to enable/disable drawing
revise reveal css s.t anchor tag would not cover drawing and disable drawing when slides change
sync still has bug(can't emit  object)
Fix scale and canvas size in Chrome
sync:init canvas at audience
Merge branch 'fhdrawing' of https://github.com/g21589/Prezan into fhdrawing
Remove ./server/node_modules/*
Update install files
sync freehand drawing path
fix bug in initial canvas position
solve mouse position offset problem
Fix scale bug in Chrome
Merge fhdrawing branch