rose suite-log: source.html: fix undef suite title

Title was displayed as undefined. Now use an AJAX call to load the main
JSON file to obtain the information. This should be more robust than
having to rely on it being parsed as an argument from index.html.
Merge pull request #787 from matthewrmshin/fix.rose-suite-log.source

rose suite-log: source.html: fix undef suite title