Remove old dource code link. Add source code link for svn and git.
* download.php: document perl 5.20
* download.php: add amanda-3.3.6-with-swig-3.0.2.tar.gz
* download.php, index.php: 3.3.6 release
* download.php: fix
* download.php, index.php: 3.3.5 release
* index.php, download.php: 3.3.4
* download.php: new svn link for sourceforge repository
* index.ph, download.php: Add 3.3.3 release
* index.php: 3.3.2