Bumped version number to 1.12.1
Fixed|Hexen: Reading a savegame with no ASEG_END (otherwise intact)

While playing through Hexen's 2nd hub, for some reason a savegame
was produced for the hub map that was otherwise fine except it lacked
the ASEG_END marker.

This special case is now accepted, although it remains unclear why
the savegame was created incorrectly in the first place.
Updater: Don't open a dialog when update available

When the automatic updater notices that an update is available, only
the small notification is now shown. The user can then click on the
notification or select Check for Updates in the menu.

This improves usability as the dialog is no longer forcibly
interrupting the user.
Fixed|Hexen: Overly large hub ending messages

Scaled the hub ending messages smaller so that all the text fits
on the screen.

The font metrics are not the same as in the original game...
Updater: Notification uses accent color when update available

Now the small notification icon uses the accent color if an update
is available, so that it is visually distinct from a "ongoing check"
notification.

Also, clicking on the notification icon will dismiss it unless a
download is in progress.
Fixed|libgui: Build failure in the dummy DisplayMode

The dummy version of the native DisplayMode routines had not been
updated since the latest changes to the API.
Fixed: Build failure (invalid operands)

gcc 4.6.3 on Raspbian says that '&&' cannot take int and va_list as
operands. The variable argument list parameter should never be null,
so removed the test.
qmake: Don't link libgui to the game plugins

A server build does not include libgui, so the plugins shouldn't
rely on it at this stage.
UI|Client|AudioSettings: Added toggle and default for sound-overlap-stop

IssueID #1629
UI|Client|Default Style: Color for scroll bar indicator

ScrollAreaWidget now allows specifying a color to be used for the
scroll indicator.

CommandWidget now uses an "inverted" color in the completions popup
document's indicator to make it more visible.

IssueID #1588
Fixed|Console: Reshowing a previously dismissed autocompletion popup

Any popup can be manually dismissed by clicking outside it. Previously
it was not possible to restore the autocompletion popup after it was
dismissed without starting a new autocompletion action.

This commit fixes #1590.