Plugin version 1.0 changes 6

+Changes in plugin editor screen:
+implemented  code to add & remove values of the about properties list.
+added new button to strip menu to have Embedded Code in XML or separate
file, saving preference to app setting.
+New app setting for "EmbeddedCode" in the XML format of the plugin or
use a separate .cs file.
+correction on cardinality of links in DTD for plugin XML format v.1.0-
+ Text of heading of about properties list box changes seeing the
version of plugin.
+ Changes control also see modifications on about properties list.
+ Added methods for double click on splitters to hide error list &
about/reference area (CODE TO BE COMPLETE).