commitctx: return a richer object from _prepare_files
Instead of returning a lot of different list, we introduce a rich object that
hold all the file related information. The unique object help with data
consistency and simply functions arguments and return.
In the rest of this series we will increase usage of this object to simplify
more code.
{
// 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)
}