Re-submit fix #33 version 2
Re-submit fix #33 version 2

As ian4hu pointed out in [#33](https://github.com/SublimeLinter/SublimeLinter-html-tidy/pull/SublimeLinter#33), Linter.which() called from within the HtmlTidy class definition resulted in an early invocation situation in which a fail test resulted for Linter's settings, _paths_ in particular, prior to any setting being cached.
Changes to fix this.
SublimeLinter/SublimeLinter-html-tidy