newt - Ensure split app gets all loader pkgs.
newt - Ensure split app gets all loader pkgs.

Previously, newt calculated the set of application packages by following
the dependency graph.  This isn't quite right.  Even if an app package
doesn't explicitly depend on a loader package, the app still needs to
know about the package so that it will get initialized during the second
stage sysinit (sysinit_app()).

Now, the application "seed" packages includes all loader packages save
for the loader app package itself.

apache/incubator-mynewt-newt,apache/incubator-mynewt-newt