add empty demo1 template
Merge branch 'production' into demo1
Merge branch 'master' into demo1
Defer tooltip creation to speed up creation of gantt chart
Merge branch 'master' into demo1_shumo

Conflicts:
	appengine/myria_web_main.py
make graph.js work without profiling chart.
fake example.
fix the problem of still using chartElement at
some places.
change the bottom to selection list style.
let query plan viz support NAryOperator.
make `queryPlan` as a class variable rather using 
the global variable `queryPlan`. since in a page 
there could be two query plans now.
add logic of switching query plan in demo.js.
Fix a small bug in visualization.
Clean up, load real data, resize fragment vis depending on number of workers
Use spaces consistently
Clean up network vis, add summary
Smaller circle with tooltip
Fix the problem where the number of workers is not determined correctly, fix axis in network vis
Clean up graph
Use pixels in graph, implement zooming