Fix typo.

Instead of writing directly via png.Encode, encode image
into a buffer first, then write the whole buffer.

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Go weekly 2012-02-07.

Example is now capexample.
To build helper tools:

   cd capexample && go install
   cd capgen && go install

This will install tools capexample and cangen into $GOPATH/bin.

sounds.go doesn't have a copyright header, because the file is generated
by a program. I don't want to make it output the copyright header,
because users can generate sounds themselves, and the copyright status
of such generated files can be different.

Server accepts parameter lang, e.g. xxx.wav?lang=en.
NewAudio and WriteAudio accept the target language.

At last!

[RIFF][following size][WAVE]fmt[...]...data[data size][padded data].

Also, update example.wav.