Modify Taglet API for standalone tags to handle inline tags taglets.jar, etc.

The Taglet class is fine for simple tags, but has limitations.

- Extend the Taglet API to enable standalone tags to handline inline tags
  (both standard and custom) in their arguments. This requires access
  to HtmlStandardWriter and Doc. This is currently done
  by extending AbstractExecutableMemberTaglet

- Extend the Taglet API to enable access to HtmlStandardWriter.
  This is currently done by extending AbstractInlineTag

- Extend the Taglet API to enables multiple taglets to be
  put in a single jar file (taglets.jar) and loaded with a single option.
  A suggestion for this can be found under Suggested Fix.

Name: dk30142 Date: 06/29/2002


A major goal is that a third party developer should be able to reimplement a standard
tag with *all* of its standard functionality, including supporting inline tags.
All of this should depend only on the new internal API (SPI) resulting from the refactoring
work. That is, taglets should not break in the future if we later reimplement the
standard doclet.
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