Patch 2

Unless I'm missing something, I think this is a few for #77 (`<textarea>` & `<pre>` whitespace/collapsing problems). After a bit of testing, I realized that by removing `_canTrimWhitespace(...)` and `_canCollapseWhitespace()` fixed the bug. Reasoning: At this point, the `stackNoTrimWhitespace` has already been popped and checking for `!stackNo...length` gives us the green light to do further checking (i.e. `smart` collapse or `trim`). Having `_canCollapseWhitespace(currentTag, currentAttrs)` caused the logic to return false for `pre` and `textarea`. I'm sending this pull request to spark further discussion; I'd love to get some peer review/feedback on this change.