HTML help support

Problem type developers can take advantage of the internal HTML browser if they wish to provide online help.
The GiDCustomHelp procedure below is how you can show help using the new format:

GiDCustomHelp ?args?

where args is a list of pairs option value. The valid options are:

• -title : specifies the title of the help window. By default it is "Help on <problem_type_name>".
• -dir : gives the path for the help content. If -dir is missing it defaults to "<ProblemType dir>/html". Multilingual content could be present; in such a case it is assumed that there is a directory for each language provided. If the current language is not found, language 'en' (for English) is tried. Finally, if 'en' is not found the value provided for -dir is assumed as the base directory for the help content.
• -start : is a path to an html link (and is relative to the value of -dir).