Merged composition dictionary into InputMethodContext interface.
Add 'segments' property.
Clarification about focus and input event for non-editable element.
Add 'attribute' so respec can parse the definition properly.
Remove 'composition' attribute for real.
Remove 'enabled' property and open() method.
Add note for visualizing segmented clauses.
Clarification for the scope of setCaretRectangle()'s and
setExclusionRectangle()'s values.