Signingkey change and return values

[ingig]

In this pull request there a multiple breaking changes so DELETE your .build folder

BREAKING CHANGES:

• Plang uses now Ed25519 for signing messages instead of Eth key
• Indexes start from 0 not 1. It´s not practical with underlaying language using 0. %position% variable in loop starts at 0
• Events are moved to new location in the .pr file

Those are the big ones. Just delete .build folder and rebuild everything

Many more changes