coyote: CGKML_FEATURE__DEFINE

Description
This program implements the KML abstract FEATURE class. For 
reference, see  the `Google KML Reference Documentation `.
A Feature object extends a KML Object, and both should be inherited by,
for example, a KML Overlay object, which further extends this KML abstract
class.
Categories
Graphics, FileIO
Examples
See the `cgKML_File` object for examples of how to create a KML file.
Author
FANNING SOFTWARE CONSULTING::
   David W. Fanning 
   1645 Sheely Drive
   Fort Collins, CO 80526 USA
   Phone: 970-221-0438
   E-mail: david@idlcoyote.com
   Coyote's Guide to IDL Programming: http://www.idlcoyote.com
History
Change History::
   Written, 28 October 2012 by David W. Fanning.
   Fixed typo in spelling of N_Elements. 16 Jan 2013. DWF.
Copyright
Copyright (c) 2012, Fanning Software Consulting, Inc.
e purpose of this method is to establish a KML Feature object class. For reference, see
tps://developers.google.com/kml/documentation/kmlreference#feature.
Keywords
abstractview: in, optional, type=object
    Defines a viewpoint associated with any element derived from Feature. Either a cgKML_Camera or
    cgKML_LookAt object.
address: in, optional, type=string
    A string value representing an unstructured address written as a standard street, city, 
    state address, and/or as a postal code. You can use the 
tag to specify the location of a point instead of using latitude and longitude coordinates. (However, if a is provided, it takes precedence over the
.) author: in, optional, type=struct An anonymous structure with two tags. Tag "NAME" is a string that gives the author's name, and tag "LINK" is a string that provides a URL to the author's web site. description: in, optional, type=string User-sullied content that appears in the description balloon. Can be complicated. See the KML Reference for "Feature", cited above. extendeddata: in, optional, type=structure A scalar or vector of anonymous structures containing a tag NAME and a tag VALUE, which are both strings. An optional third field DISPLAYNAME can also be present. See the reference (https://developers.google.com/kml/documentation/kmlreference#extendeddata) for additional information. open: in, optional, type=boolean, default=0 This keyword specifies whether a Document or Folder appears closed or open when first loaded into the Places panel. The default is to show the Document or Folder collapsed rather than expanded. phonenumber: in, optional, type=string A phone number. Used only by Google Maps Mobile. placename: in, optional, type=string This is the element in a Feature object. It is user-defined text that is used as the label for an object in Google Earth. snippet: in, optional, type=string A short description of the feature. This description is displayed in the Places panel under the name of the feature. If not supplied, the first two lines of the `Description` are used. styleurl: in, optional, type=string The URL of a