PlaceHolder [edit]

TODO

- new PlaceHolder(Document session, Number length, Number pos, String others, String mainClass, String othersClass)

TODO

session	Document	Required. The document to associate with the anchor
length	Number	Required. The starting row position
pos	Number	Required. The starting column position
others	String	Required.
mainClass	String	Required.
othersClass	String	Required.

Emitted when the cursor changes.

Emitted when the place holder updates.

TODO

TODO

Hides all over markers in the EditSession that are not the currently selected one.

TODO

TODO