RFR: 8176453: Javadoc search: there are issues with generics in parameters

[Hannes Wallnöfer]

Please review and test this patch to escape < and > characters in search 
results to HTML &lt; and &gt; entities.

Issue: https://bugs.openjdk.java.net/browse/JDK-8176453
Webrev: http://cr.openjdk.java.net/~hannesw/8176453/webrev.00/

This fixes rendering of search results for search terms containing generics 
such as „map<str“.

Thanks,
Hannes