Fix assert event position

[simov]

Fixes #18
Closes #19

Thanks for the thorough explanation, @isaacs , my solution was to simply emit any cached single line assert result, or if not followed by yamlish starting line, before parsing (respectively emitting) anything else.

// assert from previous line
if (this.current) {
  var indent = line.match(/^[ \t]+/)
  if (indent) {
    indent = indent[0]
    // not beginning of yamlish, and not already in yamlish
    if (line !== indent + '---\n' && !this.yind && !this.yamlish) {
      this.emitResult()
    }
  // single line assert
  } else {
    this.emitResult()
  }
}

Then I changed the position of all of the assert events for single assert lines one by one by hand, just to make sure the logic is correct (except tap-tests-stdout and tap-tests that I generated). So even if you don't like my solution, you can still pick the tests fix commit and test your solution against that, because this is the correct event order anyway.

[isaacs]

Fails to parse valid tap.

TAP version 13
1..1
not ok 1 - please keep my diags
  # the diags are coming
  ---
  after: comment
  ...

This will cause it to lose the diags and emit them as "extra" lines.