Use official tcpdf package to avoid conflicts

[barryvdh]

Is there a reason that tcpdf is included instead of required via https://github.com/tecnickcom/TCPDF ?

This could lead to autoload problems, because tcpdf is required in the global namespace. If this version is copied directly, I would suggest namespacing the tcpdf classes to avoid potential conflicts (eg. other libraries using tcpdf)

[tamala73]

Is there a way to fix this? I do have a conflict -- trying to use this with elibyy\tcpdf