acai: add extended information to output

[MartinHelmut]

The currently provided informations are totally fine for the current use case. But to extend the use case additional informations could be provided. The following informations are easily extractable:

• full commit message (currently it only uses the first paragraph)
• commit body
• reference (sha commit string)
• code changed + change status (unmodified, added, deleted) + line number
• author

This could extend the current structure like the following:

// Fixes:
[
    {
        "message": "commit message that introduced a fix",
        "fullMessage": "...",
        "body": "...",
        "ref": "1a6ab7b34e2d660d1509e964134a8acd3bd00477",
        "time": 1500000000000,
        "files": ["relative/path/to/file1.ext", "relative/path/file2.ext"],
        "change": {
            "relative/path/to/file1.ext": {
                "status": 0,
                "diff": "...",
                "lineNumbers": [10, 11, 12, 14]
            },
            "relative/path/file2.ext": {
                "status": 2,
                "diff": "..."
            }
        },
        "author": {
            "name": "...",
            "email": "..."
        }
    },
    {
        "message": "another bug was closed",
        "fullMessage": "...",
        "body": "...",
        "ref": "3aef0b32541583975a9236f6fd68ffd71239bc8d",
        "time": 1500000000001,
        "files": ["relative/path/file2.ext"],
        "change": {
            "relative/path/file2.ext": {
                "status": 1,
                "diff": "...",
                "lineNumbers": [142, 143, 144]
            }
        },
        "author": {
            "name": "...",
            "email": "..."
        }
    }
]

[MartinHelmut]

Example code for code changes: https://github.com/nodegit/nodegit/blob/master/examples/diff-commits.js