VM: Remove fee for VM calls

[orogvany]

Update API to reflect

Fixes #100

[honeycrypto]

This didn't pass my tests. I cannot synchronise Testnet from block 0. Once it arrives to the first CREATE/CALL which had some fee already, synchronisation stops with this in the log:

WARN     Block            Transaction result does not match for TransactionResult [code=INVALID_FEE, returnData=, # logs=0]
ERROR    SemuxSync        Invalid transactions
INFO     SemuxSync        Invalid block

I am at develop branch with the latest commit from RC2 PR #112

[orogvany]

Ah good call. For early blocks,a fee is permissible. Will remove check there