Address all the late feedback that came in after the merge.
Handle variable interpolation and semicolon in after LESS mixin parameter variables correcly.
Also process skipping to closing brackets properly for nested rules and at-rule blocks.
Fix the infinite loop introduced by previous commit.
Attach onActiveEditorChange event listener only if Live Preview is active.
Handle interpolated variable in property name.
A better way of handling variable interpolation that has any prefix of @{property}.
Handle variable interpolation in selector in addition to interpolated properties.
Implement a generalized solution for variable interpolation in properties to handle the different syntax between LESS and scss.
Merge pull request #8844 from adobe/rlim/parse-less-and-scss

Changes for all the late feedback of pull request 8720.