This patch combines several high level changes which are conceptually
independent but in practice rather intertwined.
* Add a "state" property to ShellApp which reflects whether it's
stopped, starting, or started. This will allow us to later clean
up all the callers that are using ".get_windows().length > 0" as
a proxy for this property
* Replace shell_app_launch with shell_app_activate and shell_app_open_new_window
A lot of code was calling .launch, but it's signficantly clearer
if we call this ".open_new_window()", and later if we gain the ability
to call into an application's menu, we can implement this correctly rather
than trying to update all .launch callers.
* Because ShellApp now has a "starting" state, rebase panel.js on top of
this so that when we get a startup-notification sequence for an app
and transition it to starting, it becomes the focus app, and panel.js
cleanly just tracks the focus app, rather than bouncing between SN
sequences. This removes display of non-app startup sequences, which
I consider an acceptable action in light of the committed changes
to startup-notification and GTK+.
https://bugzilla.gnome.org/show_bug.cgi?id=614755
The two parts were mapping windows to applications, and
recording application usage statistics. The latter part
(now called ShellAppUsage) is much more naturally built on top of
the former (now called ShellWindowTracker).
ShellWindowTracker retains the startup-notification handling.
ShellWindowTracker also gains a focus-app property, which is
what most things in the shell UI are interested in (instead of
window focus).
ShellAppSystem moves to exporting ShellApp from more of its
public API, rather than ShellAppInfo. ShellAppSystem also
ensures that ShellApp instances are unique by holding
a hash on the ids.
ShellApp's private API is split off into a shell-app-private.h,
so shell-app.h can be included in shell-app-system.h.
Favorites handling is removed from ShellAppSystem, now inside
appFavorites.js.
Port all of the JavaScript for these changes.
https://bugzilla.gnome.org/show_bug.cgi?id=598646
