resolves #3 escape annotations & process escaped closing comment

This patch is by no means perfect. But it serves as a preview of how we can allow verbatim source code in the Javadoc.

It appears it's possible to process and replace the raw comment text before allowing Javadoc to parse out tags. This gives us the opportunity to substitute `@` characters in front of annotation names with `{@literal @}` so that the developer doesn't have to dirty up the Javadoc.

Perhaps a hack. But it sure does make things nicer (see the Javadoc on Asciidoclet for an example).