Add very obvious links to repositories and github

[zasran]

Currently it's fairly hard to find the links to repositories. Not sure what the best solution is, here are few ideas:

• put them in the Project menu (similar to the old rsyslog page)
• 'Current versions' block on the right could be called 'Installation' or 'Downloads' or 'Where to get rsyslog' and the headline could be a link (to a page descibed below)
• www.rsyslog.com/downloads/download-other/ and www.rsyslog.com/downloads/ could be just one page that lists all repositories as well as packages (tarballs) that one can download

Similarly I don't see obvious links to github, it would be great if they are listed together with other places where one can get Rsyslog. There is a link to github in Community block in lower right corner which is virtually invisible (maybe it's just me:)