Feature: def p()

This is the TODO on tkxxs.rb (removed on 7f65fc4d821eed58064a867be969276518fb12b6)

At this same pull request I did some crlf/lf normalization with .gitattributes and added a better .gitignore so that files under doc/ and pkg/ don't mess around anymore on the repository.

I used a StringIO to proxy the puts, print, printf transformations. (It would be pretty hard to implement a printf without this).

The code has much room for improvement. But I think it can be merged by now, mostly because of the .gitinore and .gitattribute files.