[MU-3] new beans MozillaSourceVersion, MozillaUpdate and MozillaPatch
[MU-3] UpdateFetcher uses MozillaSourceVersion, MozillaUpdate and MozillaPatch
[MU-3] Use MozillaSourceVersion in the scraper
[MU-3] Add a configuration option: interval to scrap Mozilla servers
[MU-3] add method fetching product versions in database and queueing the scraping
[MU-3] add periodic-tasks launcher
[MU-3] enable the periodic tasks on Mupee startup