Any GtkWidget creation or manipulation should be done exclusively
from the main/UI thread, thus make sure it is done that way.
Of course, evolution can freeze for a little time (depends on the message
size), until its formatting is done. It's unnoticeable with usual messages.

The zoom in shortcut (Ctrl+) can be confusing for some users because on
keyboards with a [+ =] key the '+' requires holding Shift.  To mitigate
the confusion, also accept (Ctrl=) for zoom in.

And while we're add it, also support Ctrl+ and Ctrl- on keypads, as well
as keyboards with dedicated Zoom In / Zoom Out keys.

(cherry picked from commit 8924b0bd)

The request's finish function is not called in case when the request
is cancelled, which meant that the whole data stream was leaked.

While looking at bug #721286, I found out that mail_shell_view_prepare_for_quit_cb
calls a sync of the folder changes to the server, but mail_backend_prepare_for_quit_cb
does the same thing (or even more, because it calls to synchronize changes in all folders),
thus the former is redundant and can be dropped.

Missed a case when an EMailReader is an EMailBrowser, which is not
an EMailView, which produced a runtime warning on a console when
a message was shown in a separate window (like after double-clicking it).

This breaks the string freeze for 3.10, but still better than
having a completely broken link.

See bug #721907

Another take, this time, hopefully, the final. The call to e_tree_set_cursor()
also resets the view to the selected row, which we want to avoid, thus do
not do this call, if the view was regenerated on a folder-changed signal.

There was missing a call to set CamelSession offline, which made
the other CamelService-s think they can do network operations,
while it wasn't true.

Just a couple leftovers in mail/Makefile.am.  Not needed anymore.

(cherry picked from commit ced4884e)

Some locales do not provide equivalents for am/pm (the "%p" of strftime),
thus when the user has set 12 hour format in Preferences, then the am
and pm times are the same, which confuses the widget, especially
in the appointment editor, making it hard (like impossible) to enter
pm times by selection in the time combo. An example locale is de_DE.

This got dropped accidentally in the patch for bug 709428.

(cherry picked from commit 359b7b45)