testeth -- --filltests on a blockchain test should copy the comment in the _info field

[pirapira]

For example, when src/BlockchainTestsFiller/bcValidBlockTest/callRevertFiller.json contains

{
    "callRevert" : {
        "_info" : {
            "comment" : "This test contains a message call transaction that fails by REVERT.  The interest is on the status code in the transaction receipt (though not specified in the expect section)."
        },

The comment should appear in the filled file. However, after

test/testeth -t BlockchainTests/bcValidBlockTest -- --filltests --singletest callRevert

I don't see the comment in the _info field in the filled file.