Use model units to define text boxes font size

[#57248996]
Convert text boxes font size from MML (instead of fontScale)

[#57248996]

Note that Classic MW has constant "nm to pixel ratio" which equals to
1:100. We can use in to define font size in 'nm'.
Don't force authors to overwrite all object properties in interactive JSON

[#57248996]

Previously when author wanted to overwrite text box "x" property,
he had to define its all properties in interactive JSON, e.g.:

"textBoxes": [
      {
        "text": "Separated Oil and Water",
        "x": 0.92,
        "y": 1.96,
        "layer": 1,
        "frame": "rounded rectangle",
        "fontSize": [
          0.12
        ],
        "backgroundColor": "rgb(232,231,231)",
        "anchor": "upper-left"
      }
    ]

Now it's enough to specify only options that you want to overwrite:

"textBoxes": [
      {
        "x": 0.92,
        "y": 1.96
      }
    ]
Tweak / fix / polish interactives after text boxes font size fix

[#57248996]
Revert "model fontScaling when actual aspectRatio != aspectRatio"

This reverts commit bb82fd4328ab932763ebd52d66bab5224c21e078.
Revert "when model is same size font will render the same"

This reverts commit 9cffd50d816d177e5d80969e0a45e6ad002fd4e3.
Revert "handle font-size for smaller and larger modelViews"

This reverts commit 3db1d3622cc84ee20d3059ce9f97bf7dfecea376.
Revert "isolate modelView from Interactive aspectRatio/font-scaling"

This reverts commit 1b4bc3db16259d0cffb5c03e00b00b179f8de138.
Update text fixtures after changes in text boxes definitions

[#57248996]
Fix text boxes in 'particleMixing'

[#57248996]
expose existing image properties to scripting api

[#57828832]
on more model font-scale layout test Interactive

[#57248996]
This adds a fifth interactive for testing font-scaling
issues in the model container.

This one adds a fontScale attribute with a value of 1.5
to the Interactive definition.
Merge branch 'master' into textbox-fix

Conflicts:
	src/interactives/interactions/particleMixing.json
Bump jQuery to 2.0.3
adasdasdasdas
Tweak "Particles Mixing" interactive (text boxes)

[#57248996]
Merge pull request #44 from concord-consortium/textbox-fix

Textbox font-size fix
QD: Use Lifetime to decide whether atoms can be deexcited through collisions

As with Classic MW, atoms should not be deexcitable through collisions
immediately after being excited, but are instead stable for a certain
lifetime. After this lifetime, a collision can deexcite them either via
radiation or radiationless transmission.

Kept the stochastic method of determining spontaneous emission.

The stochastic method would not be easily useable for thermal transmission
because we would need to know the frequency of collisions.

[#58011196]
QD: Use lightsource property from model definition

[#56364006]
Fix model JSON editor when model is defined inside Interactive JSON

[#58080048]