Add support for FTPS command to set the DataChannelProtectionLevel (VFS-412).

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/vfs@1448606 13f79535-47bb-0310-9956-ffa450edef68
Update changes.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/vfs@1448642 13f79535-47bb-0310-9956-ffa450edef68
Update contributors#.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/vfs@1448644 13f79535-47bb-0310-9956-ffa450edef68
ConfigBuilder does not consider system properties for the value of SoTimeout and Encoding.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/vfs@1448645 13f79535-47bb-0310-9956-ffa450edef68
Drop obsolete test.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/vfs@1448665 13f79535-47bb-0310-9956-ffa450edef68
Deprecate FtpsFileSystemConfigBuilder.setFtpsType and FtpsFileSystemConfigBuilder.getFtpsType in favor of FtpsFileSystemConfigBuilder.setFtpsMode and FtpsFileSystemConfigBuilder.getFtpsMode which use new enum FtpsMode instead (VFS-462).

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/vfs@1448668 13f79535-47bb-0310-9956-ffa450edef68
FileSytemConfigBuilder supports system properties for the value of enum-based configuration entries (VFS-463).

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/vfs@1448689 13f79535-47bb-0310-9956-ffa450edef68