Add encoding parameter to events, etc.

[webdeck]

I have a calendar URL that is encoded in latin_1 (olympic events provided by ecal.com)

It would be great if the top level events() API allowed overriding the encoding of UTF-8. Instead, I have to invoke ICalDownload directly so that I can specify the encoding.

[eigenmannmartin]

Thank you very much for this bug report. I think this is a duplicate of this one: #128