#64 Add missing includes for some versions of gcc

[pollux]

Hi,

Some (recent) versions of g++ make an error when using printf and similar functions without including cstdio.
The attached patch adds some missing includes. However, it was created for an older version of vym, so it still applies but I have not checked if there may be duplicate includes.

Best regards,
Pierre

[In Silmaril]

Pushed to git, thanks.