Add .dropboxignore directory to exclude folders without using selective sync

@jmmk

Yes, I'm aware that many people want a pattern-based solution, and I would warmly welcome it. That said, you can't definitively say that that is what this "idea" is all about when the OP himself suggested a possible non-pattern based approach that you consider unhelpful in the idea description that people have voted for.

Again, I just wanted to point out that it is already possible to easily exclude local folders like node_modules from syncing, as a number of commenters have implied that they did not realise this was possible even on an individual, manual basis.