All this so EMFolderTree can submit EActivity instances for async ops.
You can obtain an EMailSession from an EMailBackend, but not vice versa.
Creates lots of pretty ripples in the mail code, but ultimately reduces
complexity. So it's a code cleanup of sorts.
It shouldn't be needed for plugins that live in the evolution source tree anyway
since they should just use the translation domain they inherit from main().
With unintrusive error dialogs gone, we can cut some unnecessary bits
out of EActivity.
I'm also adding a new enum property called "state", which is one of:
E_ACTIVITY_RUNNING
E_ACTIVITY_WAITING
E_ACTIVITY_CANCELLED
E_ACTIVITY_COMPLETED
The state of an activity must be explicitly changed. In particular,
when the user cancels an activity the state should be set only after
confirming the operation has been cancelled and not when cancellation
is requested (e.g. after receiving a G_IO_ERROR_CANCELLED, not when
the GCancellable emits "cancelled"). EActivityBar and EActivityProxy
widgets have been updated to make this distinction clearer in the UI.
E_ACTIVITY_WAITING will be used when activities have to be queued and
dispatched in sequence, which I haven't written yet.
And generate GTypes for each of them in e-mail-enumtypes.[ch].
Also, the glib-gen.mak script forced me to add a <mail/e-mail.h>
top-level header, which really isn't a bad idea anyway.
TODO: We should do this for calendar and addressbook too.
Global variables in shared libraries are a bad idea. EMailBackend now
owns the MailSession instance, which is actually now EMailSession.
Move the blocking utility functions in mail-tools.c to e-mail-session.c
and add asynchronous variants. Same approach as Camel.
Replace EMailReader.get_shell_backend() with EMailReader.get_backend(),
which returns an EMailBackend. Easier access to the EMailSession.
