Add support for GutterOnRight and GutterOnTop

[PrzemyslawKlys]

• gutterAtTop (Position Gutter At Top of Page)

This element specifies that a given WordprocessingML document’s gutter shall be positioned at the top of the document’s pages when the document is displayed. A gutter is the white space formed by the inner margins of two pages facing one another; such as the white space between the text on pages of a book when the book is opened.

If this element is omitted, then the gutter shall not be positioned at the top of the page. If the mirrorMargins (§17.15.1.57), bookFoldPrinting (§17.15.1.11), bookFoldRevPrinting (§17.15.1.13), or printTwoOnOne (§17.15.1.64) elements are used within a given document, the gutterAtTop element shall not be used. Rather, the gutter shall be positioned automatically as necessary to enable the printing and page layout capabilities of these settings.

[Example: Consider a one page WordprocessingML document with a 1,440 twentieths of a point (one inch) top margin and gutter, and a 720 twentieths of a point (one half of an inch) header. Consider also, that the gutter must exist at the top of the document's pages. This requirement is specified using the following WordprocessingML in the section properties:

• rtlGutter (Gutter on Right Side of Page)

This element specifies that the page gutter shall be placed on the right side of the page for this section only. The page gutter defines the amount of extra space added to the specified margin, above any existing margin values. [Note: This setting is typically used when a document is being created for binding, in order to ensure that the resulting margins are present after the binding gutter is consumed by the printed matter binding. end note]

If the gutter is set to the side of the page by the omission of the gutterAtTop element (§17.15.1.50), then each section's gutter is placed at the left by default, unless that default is overridden by the rtlGutter element.