Builds a help search index for a plug-in by looking for the org.eclipse.help.toc extensions in the provided manifest file. Search index is only created if index path is specified in the extension. Index will contain data for all the topics listed in all the TOCs declared in the plug-in.

If the index is created for a fragment, the manifest must point at the referenced fragment plug-in, while the destination should be the fragment itself.

Starting from the provided destination directory, index for each locale will be placed in a directory with the following path:

                  destination/nl/country/
                  
                  or
                  
                  destination/nl/country/language/ 
 

The relative directory specified in the index element of the org.eclipse.help.toc extention will be created in each of the locale-specific paths (one per locale).

An instance of HelpIndexBuilder can be cached and used multiple times for different manifest and destination values.