Replace nm2px with model2px after change of view public API
Implement serialization of the graph component

[#43328491]
Add 'getInteractiveState' to the post message API and use it

[#43328491]
use renamed update() method in MD2D benchmarks
Add 'alert' module

[#43484231]

Simple module providing way to communicate errors to user.
It just uses 'alert' for now, but in the future, it will be easy
to replace it with another solution.
Catch and display errors while processing components definitions

[#43484231]
Add initial components-metadata file

[#43484231]

For now, only buttons and checkboxes have defined metadata.
Work in progress.
Validate button and checkbox definitions using metadata

[#43484231]
WIP: Add restful routes for posting interactives (mirrors of md2d_model)
update couchrest_model to 2.0 beta.
WIP: Temporarily use [Object] types to serialize components, models.
WIP: Script to slurp in Interactive json files from FileSystem to DB.
Change test framework to spec. Use guard to run tests in dev mode.
remove AR fixture helpers from rspec-rails generated spec_helper.rb
Add webmock to mock out http requests for certain tests.
Add Group Model.
Sample json file for interactive list, and a helper to read sample files
Nest of parser classes, and spec tests for top interactive_list_parser.
very minor formatting changes.
Simplify open-air base references with UriHelper and tests.