Remove interactive JSONs, leave only 9 examples

[#66423860]
Remove imported models

[#66423860]
Update Makefile (do not convert models, process interactives etc.)

[#66423860]
Add models used by example interactives

[#66423860]
Remove manually created models

[#66423860]
"Sun on ground" example: add missing image

[#66423860]
Change Lab index page

[#67396368]
Remove unnecessary sites from Lab repo (e.g. interactives.html)

[#66423860]
Remove doc, examples and experiment pages

[#67396368]
Update Makefile

[#67396368]
DG Exporter: use requirejs to get Lab.config (instead of global var)

1. Cleaner.
2. Lab.config will fail in node environment (tests).
Fix tests after recent changes (separation of Lab and interactives)
Remove coffeescript compilation from Makefile

[#66423860]

All .cs files are handled by RequireJS during Lab build.