packaging: move DOWNLOADS dict to hgpackaging.downloads
We'll want to keep state in sync between multiple packaging tools.
It makes sense to share a central data structure defining downloads.
We also change the function to return the downloads entry so
callers don't have to access the global DOWNLOADS in the new
location.
Differential Revision: https://phab.mercurial-scm.org/D6085
{
// 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)
}