sparse: directly inline the `set_tracked` and `copy` wrapping
core is already aware of sparse, so lets move the handful of line of code that
deal with this for the sake of simplicity and explicitness.
= Mercurial XXX =
== New Features ==
== Default Format Change ==
These changes affect newly created repositories (or new clones) done with
Mercurial XXX.
== New Experimental Features ==
== Bug Fixes ==
== Backwards Compatibility Changes ==
== Internal API Changes ==
== Miscellaneous ==