Added message.pet.php convenience PET
Added FontAwesome!
Added default css for Paladio
Added thoth!

Thoth has been developed at https://github.com/theraot/thoth
Updated message to use FontAwesome
Renamed InvokePET to PETInvoke
Added PETInvokeOnce

To be used to include code to handle multiple elements created via PET,
by allowing to include such code only once instead of once per element.