Add support for inferring private based on the name

[arv]

This adds a command line flag called --infer-private which is a
string (defaults to ^_) which is used as a regexp for inferring
if a name is private or not.

For example:

/** C */
class C {
  /** I'm public */
  m() {}
  /** I'm private */
  _p() {}
}

Fixes #436

[arv]

I wanted to add an end to end test since this does not test that the command line flag gets passed along all the way [*] but I wasn't sure how to best do that. Any suggestions?

[*] it does from manual testing

[tmcw]

Great! The test/bin tests are where we do end-to-end testing. They don't have the same automatic fixture generation as test/test, but you could run assertions off of the output.

[arv]

I added a test to test/bin.js.

This is ready for review.

[tmcw]

On a code level, it looks good to me, but I can't see how one would turn off inference entirely; you can replace the regex with a different one, but in order to "never infer private methods", I am inferring that you would have to write a regular expression that does not match anything, and for me that's a hard thing to guess at.

[arv]

That is a good point. Two alternatives.

1. Leave infer private off by default
2. Treat an empty string as off.

I'm leaning towards 1.

[arv]

The option is now off by default. Let me know if you want me to squash the commits?

[tmcw]

👍 Excellent, yep, squash and I'll merge!

[arv]

Squashed and some minor cleanup

[tmcw]

👍 thanks, merging!