Replace generic plots with Plotly specific plots

[jini-zh]

Instead of storing a generic plot in the database, store two JSON objects --- trace and layout --- that are arguments to Plotly plotting functions.

[jini-zh]

This pull request should be merged with ToolDAQ/ToolDAQFramework#32, ToolDAQ/middleman#9, ToolDAQ/libDAQInterface#12

[brichards64]

can you make this update in the common functions.js as well

[jini-zh]

Rebased on top of current master and ported to html-Common.

In the first patch I introduced and unexported function GetPSQLJSON in functions.js which wraps GetPSQL to return its result as a JSON array. I think that this functionality should be included to GetPSQL and that functions.js needs a major overhaul in functions interfaces, so GetPSQLJSON is temporary while I'll be working on this.