Improve styles for ListLanguagesSample, make row indicator smaller, remove need for allowHtml

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@palm.com)
More updates to enyo.List:
* Better define placeholderRowIndex as the row after where we show the placeholder node
* Add pageForRow() utility method, refactor use
* Change p0RowBounds, p1RowBounds to hashes based on index
* Update positionToPageInfo() to return start/end row info, used to speed up searches
* Refactor frequent calculation into pageForPageNumber()
* Have reorderDrag offset the placeholder depending on direction of travel
* Simplify movePlaceholderToIndex and have it handle out-of-range values appropriately
* Remove unused removeHiddenNode()
* Modify getRowIndexFromCoordinate to properly account for hiddenNode and placeholderNode

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@palm.com)