campaignd: No longer allow existing add-ons with invalid names to be reuploaded

Reverts commit 88df3418f99f05f2465ace970eaa36656ff6ee0e.

We are going to branch 1.12 soon, so it's about time to get rid of this
temporary backwards compatibility measure.
wesnoth_addon_manager: Make the portmap tuple more easily diffable
Update changelog for wesnoth_addon_manager fixes

Related to commit 10df18d7cf062585334247a73dd2fe7e2702a19c and commit
ae3697d4e8e1386593c59ea978837af4b68d722c.
wesnoth_addon_manager: Add missing trailing newline to _info.cfg
addon/info: wesnoth_addon_manager wants the dependencies list in _info.cfg
wam: Write title and type fields to _info.cfg like the C++ client does
wam: Make our _info.cfg's look identical to the C++ client's

To achieve this, add the same leading comment section ("do no edit this
file", etc.) and use the same indentation format as the C++ engine, and
don't use quotes around the uploads attribute value (it's an integer).
Update changelog for recent wam changes
gui2/ttext_box: Workaround text AA issue with transparent background

... by making it not transparent.

For some reason, on Linux the antialiasing of the textbox text contents
looks slightly off when the background is a transparent (a != 255)
color. This does not happen when a solid color (a == 255) is used
instead.

Since Cairo AA is broken horribly with ClearType on Windows atm I'm not
really sure this specific bug also happens there.

To keep the intended effect of ebc214ff124ad4bb79700b509b1369766481c842,
I took a couple of screenshots of the textbox widget in both its enabled
and disabled states and averaged the background colors with the GIMP to
get an approximation of the result of blending the transparent overlay
from the GUI__BACKGROUND_COLOR_* macros with the standard dialog
background.
gui2/ttext_box: Add a 'transparent' backgroundless variant for WML [message]
Healer support MAI test scenario: change event from die to last breath
Forest Animals MAI: make the rabbit-type animals replay safe

They need to be put on the map and taken off using ai.synced_command(),
otherwise it causes OOS errors.
gui2/tscreenshot_notification: New GUI2 dialog shown when taking screenshots

It includes the following features:

 * A cleaner and more structured message display
 * Buttons to copy the screenshot file path to clipboard or open it with
   an external application defined by the platform
 * An additional button to browse to the screenshots folder using an
   external file manager defined by the platform

It also breaks the scons build. This will be addressed by the next
commit.
scons: Link libwesnoth_extras.a into wesnoth twice

Solves linker errors caused by hotkey/command_executor.o's newly-gained
dependency upon gui/dialogs/screenshot_notification.o.
Update changelogs and RELEASE_NOTES
Merge branch 'staging/feature/screenshot-notifications'