Fix issue 351: Vertical text alignment

NIAttributedLabel.verticalTextAlignment stopped working correctly in
commit c856b9b.
Add shadow offset support for NIGroupedCellBackground.
Merge pull request #383 from jverkoey/offset

Add shadow offset support for NIGroupedCellBackground.
[css] Add UIKit import to NIUserInterfaceString.h.
Add methods to get information from an NITableViewActions object about which cell accessory it would provide for a particular object
Merge pull request #388 from darrenw/TableActionsInfo

Add some object-state methods on NITableViewActions
Add support for defining explicit links in NSAttributedString
Functionalize processing of links from NSAttributedStrings
URL Encode charactersToLeaveUnescaped
Provide a way to suppress the cell divider in NICellBackgrounds using a category method on UITableViewCell.
Use NIGroupedCellAppearance protocol instead of category method to suppress the cell divider.
Change drawCellDivider to drawsCellDivider in the NIGroupedCellAppearance.
Fix the comment style in NIGroupedCellAppearance.
Merge pull request #396 from jverkoey/cell_divider

Provide a way to suppress the cell divider in NICellBackgrounds.
Bug fix: Correctly grouping the bitwise operation for drawDivider in NICellBackgrounds.
Merge pull request #397 from jverkoey/cell_fix

Bug fix: Correctly grouping the bitwise operation for drawDivider in NICellBackgrounds.
Merge pull request #393 from agassiyzh/master-jverkoey

URL Encode charactersToLeaveUnescaped
Update documentation for Link attribute.
Merge pull request #391 from Joe030984/master

Add support for settings links in NSAttributedString
Don't override -[UIViewController shouldAutorotateToInterfaceOrientation:] if deployment version is iOS 6 or above