Folds customization

[zdm]

Following global variables added:

let g:javascript_fold_blocks = 1
let g:javascript_fold_comments = 1
let g:javascript_fold_functions = 1

[zdm]

This PR allows users to choose, what to fold: comments, functions, other code blocks.

[vokar]

Any possible progress regarding merging this PR?

[amadeus]

Unfortunately I am personally opposed to merging this - I don't really like converting a ton of syntax definitions to exec blocks, and we lose syntax highlighting.

[zdm]

I agree, that syntax is pretty ugly.
But is there is another way to fold functions only?