Shared state async insert rate

[javierbrk]

There is a maximum insertion rate into shared state async associated to the update_interval, when you try to insert information before update_interval shared state will fail and wont inform about it.

Successive calls will end up writing.

--minimum renewal for mesh wide was 30s, once written the user hast to wait until ttl is 2400 - 30.

example: this is not writable

    {
        "key": "upgrade_state",
        "value": {
            "mAuthor": "LiMe-1f73aa",
            "mTtl": {
                "xint64": **2376**,
                "xstr64": "**2376**"
            },
            "mData": "NOT_READY"
        }
    }

is writable

        "key": "upgrade_state",
        "value": {
            "mAuthor": "LiMe-1f73aa",
            "mTtl": {
                "xint64": **2367**,
                "xstr64": "**2367**"
            },
            "mData": "NOT_READY"
        }