Ontology contract is different from NEO contract

[johnny7861532]

Ontology using GO to rewrite NEO VM, so need to modify NEO contract in order to compile.
Ex: has_key do work on NEO but not on Ontology.

[johnny7861532]

Ontology is very different from NEO, the do have many in common, but the codebase are totally different.

Ontology got two different way to call a contract:

1. PreExec, free of charge but read only
   ./ontology contract invoke --address fb9dade88e85e7770bbb41a49091c64b53b4ea45 --prepare --params string:owner,[string:tester,string:AGa9bx6U34QxfSmeyEV9LL1DbUD4FVyPKK] --return string
2. Invoke, pay with ONG, write data to the blockchain.
   ./ontology contract invoke --address fb9dade88e85e7770bbb41a49091c64b53b4ea45 --params string:Register,[string:johnny,string:AGa9bx6U34QxfSmeyEV9LL1DbUD4FVyPKK] --gaslimit 200000