#69 added commons-net ftp to pom
 #69 added FTP as ACCESS_HANDLER_TYPES
 #69 created first version of FTPAccessHandler
 #69 register FTPAccessHandler as handler in WebAccessManager
 #69 use HttpDownload also as Ftp Download
 #69 created HttpOrFtpDownload

HttpOrFtpDownload extends HttpDownload and adds the functionality that
it can also make Ftp-downloads.
Merge branch 'feature/69-ftp-downloads' into dev