revlog: create a iteration of a _InnerRevlog object within the revlog The goal of this object is to isolate a sub-API that can be implemented by a compiled object (e.g. Rust). So the boundary of this object will be arbitrary depending of what can we easily implemented in the Compiled code. For now, we start simple, and move the code that manage the IO objects in the inner object. More will come in the coming changesets. Note: the object definition could live in the different module to thin the `revlog.py` file, however there are other better candidate for extraction first and I have enought patch stacked on top of the this one for the split in this patch not to be worth it. So I leave this to future me.

{
    // Enforcing
    "eqeqeq"        : true,     // true: Require triple equals (===) for comparison
    "forin"         : true,     // true: Require filtering for..in loops with obj.hasOwnProperty()
    "freeze"        : true,     // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
    "nonbsp"        : true,     // true: Prohibit "non-breaking whitespace" characters.
    "undef"         : true,     // true: Require all non-global variables to be declared (prevents global leaks)

    // Environments
    "browser"       : true      // Web Browser (window, document, etc)
}