Bug 161383 Support page-break-inside property on report item
Need support page-break-inside property on report items
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/metadata/ElementDefn.java
* "private style" that includes all the style properties relevant to that
 * element. In practice, any element type that has a style treats style
 * properties as though they were actual properties of the element type itself.
 * <p>
 * The meta-data file defines the style element, and this definition includes a
 * set of properties. Most of these represent properties that are to be applied
 * to elements that have that style (color, font, highlighting, etc.) A very few
 * apply to the style element itself (name, extends). To represent this, the
 * "shared" style properties are marked with an "isStyleProperty" attribute.
 * Anything so marked will associate with elements that have a style.
 * <p>
 * Other elements indicate if they have a style. In general, only the most base
 * element in a hierarchy sub-tree has this indication. All elements derived
 * from such an element also implicitly have a style. That is, a derived element
 * cannot "turn off" the style if one of its ancestors has a style. Let's use
 * the term <em>styled element</em> for one that has a style.
 * <p>
 * A styled element will present the style properties as though they were
 * properties of that element itself. This is done during the meta-data setup
 * process by copying each of the style properties from the style into the
 * styled element. The copy is done only for the most-base element in an element
 * type subtree that has a style. (Elements further down the tree automatically
 * inherit these properties in the normal way.) In practice, the implementation
 * copies a reference to the property, rather than the property itself.
 * <p>
 * However, styles have a wide range of properties, not all of which are
 * relevant to each element. Indeed, there are few elements that use all the
 * style properties. It would be confusing to the user to see a set of
 * irrelevant properties. Therefore, the meta-data file identifies the style
 * properties that are relevant to any given styled component. Only these are