Fix typos and formatting problems.

[bennettbuchanan]

In convert.js:

• The private function ancestorNamespaceValue is undocumented.
• The public function toHTMLTree is undocumented.

  In domlistener.js:

• The addHandler method does not have a type documented for the selector parameter.

  In domutil.js:

• The public function indexOf is undocumented.

  In domutil.js:

• A property description of the beforeDeleteNode event is missing.
• Property descriptions of the insertNodeAt event are missing.
• A property description of the setAttributeNS event is missing.
• Property descriptions of the setTextNodeValue event are missing.

  In modes/test/test_mode_validator.js:

• The public function Validator is undocumented.
• The public method validateDocument of the function Validator is undocumented.

  In tree_updater.js:

• The property description for the event deleteNode is missing.
• The property descriptions for the event insertNodeAt are missing.

  In serializer.js:

• The function serialize is exported but does not appear in the API.

  In validator.js:

• The description of the parameter root for the class Validator is incomplete.
• The description of the parameter attributes for the method possibleAt is missing.

  In dloc.js:

• The function DLocRoot has a @classdesc tag but is missing a @class or or @constructor tag.
• The methods nodeToPath and pathToNode of the class DLocRoot were not exported. (See previous.)

  In guiroot.js:

• The function GUIRoot has a @classdesc tag but is missing a @class or or @constructor tag.
• The methods nodeToPath and pathToNode of the class GUIRoot were not exported. (See previous.)

  In mode_validator.js:

• The class ModeValidator has a @classdesc tag but is missing a @class or or @constructor tag.
• The method validateDocument of the class ModeValidator was not exported. (See previous.)

  In preferences.js:

• The class Preferences has a @classdesc tag but is missing a @class or or @constructor tag.
• The methods get and set of the class Preferences were not exported. (See previous.)

The following appear twice in the index because they are either inherited events or extended classes. (I'm unsure if this matters, but it could be difficult to distinguish between two events or classes with the same name in the index):

Events:

• disabled
• enabled
• beforeDeleteNode
• changed
• deleteNode
• insertNodeAt
• setAttributeNS
• setTextNodeValue

Classes:

• Mode
• Listener
• ContextMenu