Hiding `_*` properties was a feature primarily for developers using Closure compiler and Google JS
style. We didn't realize how many people will be affected by this change.
We might introduce this feature in the future, probably under a config option, but it needs more
research and so I'm reverting the change for now.
This reverts commit 3d6a89e888.
Closes#4926Closes#4842Closes#4865Closes#4859Closes#4849
Conflicts:
src/ng/parse.js