Add methods: all(_ value: CGFloat), horizontally(_ value: CGFloat), ...

Add methods:

• all(_ value: CGFloat)
  The value specifies the top, bottom, left and right edges distance from the superview's corresponding edge in pixels.
  Similar to calling view.top(value).bottom(value).left(value).right(value).

• horizontally(_ value: CGFloat) / horizontally(_ percent: Percent)
  The value specifies the left and right edges on its superview's corresponding edges in pixels (or in percentage of its superview's width).
  Similar to calling view.left(value).right(value).

• vertically(_ value: CGFloat) / vertically(_ percent: Percent)
  The value specifies the ** top and bottom edges** on its superview's corresponding edges in pixels (or in percentage of its superview's height).
  Similar to calling view.top(value).bottom(value).

  • Added by Olivier Pineau in Pull Request #111