Split the GTypeModule loader out of EShellModule as EModule, and rename
EShellModule to EShellBackend. Backends (formerly modules) should now
subclass EShellBackend.
This commit converts EShell but breaks all the shell backends.
EActivity objects instead of numeric handler IDs. Create an EActivity,
configure it, and (optionally) connect to its "cancelled" and "completed"
signals. Then hand it to the shell view via e_shell_view_add_activity().
When finished with the activity, call e_activity_finish() and unref it.
svn path=/branches/kill-bonobo/; revision=36391
