Additionaly convert all to JSON.

 * explain all common errors once
 * drop extension, as content type is good enough
 * make requests looking like real HTTP requests, define required headers
 * explain inline possible values

(Removing trailing space at the same time).

Avoid having two same gid.

Anyway such calculation result in wrong addresses.

Thanks to this error in one transaction will not stop other one.

Note: For now it contains hardcoded data, dynamic ones like accounts.

It is required to calculate price of Payment Transaction.

It is the only way to allow them to manipulate mappings.