cmake: Add -mxsave flag to compiler flags

Fixes compilation when using GCC8.2 to compile a non-native build.

Fixes #2554.

gsdx:gtk: Improve dialog for small screen resolutions

Makes all the tabs scrollable, which makes the dialog more usable (the
OK button should always be present unless the screen is absurdly small).

Only checked on GTK3.

gsdx:gtk3: Fix fetching of monitor resolution

The user may not have configured a primary monitor, so get the
resolution of the monitor that the mouse cursor is currently located on.

gsdx:gtk+3: Adjust visual layout

Use hexpand instead of expand, and use margin-start instead of
margin-left (margin-left is deprecated in GTK+ 3.12). IMO it looks
better this way.

Also, set the properties using gtk_widget_set_* instead of g_object_set.

gsdx:gtk3: Switch to non-deprecated GTK3 API

The widget expanding issue seems to have resolved itself (probably a
change on the GTK3 end).

common: Use GCC's _xgetbv definition from GCC 8.2 onwards

The _xgetbv bug was fixed, so avoid using our own definition (again).

GameDB: Add XgKickHack to Warhammer 40K. Fixes corrupted graphics.

Debugger: Display ACC register. (#2527)

Displays/allows ACC VU0f register to be set.

SPU2-X-gui: Update gui interface.

Adjust/tidy up the gui to make it more appealing,
some bad positioning has been fixed.

Properly grey out Audio Expansion Mode text when
the option is inactive.

spu2-x:gtk3: Fix hbox/vbox deprecation warnings

spu2-x:linux: Reduce non-timestretch minimum latency to 3ms

This matches the Windows GUI behaviour.

GSdx-gui: Properly grey out Anisotropic Filtering text when the option is inactive.

GSdx-gui: Update CRC Hack Level tooltips.

Update Aggressive level tooltips.
Display the correct games that have Aggressive level crc hacks.

gsdxgl: Remove unused variables

Fixes some clang warnings.

pcsx2: Avoid trigraphs

Fixes a -Wtrigraph warning on clang.

onepad|spu2-x: Avoid -Wmissing-braces on clang

pcsx2: Add override to SysTraceLog functions declarations/definitions

Makes it clearer what is being overridden. Also avoids a
-Winconsistent-missing-override warning on clang.

GSdx: Adjust God of War II crc hack.

Extend the hack to remove the water / hell effect (vertical lines) on
interlaced mode.

Close #2533

GameDB: Add eeClampMode gamefix to Destroy All Humans 2 (ntsc).

EEClampMode to full.
Fixes material stretching across screen that appears for a split second.
Other regions could probably need the gamefix but need to be tested
first.

Close #1436

GameDB: Add EE and VU clamping mode gamefix for A.C.E. 3 the final.

EEClamping mode to Full,
VUClamping mode to Extra+Preserve Sign.

Fixes hangs/freezes on mission 2 loading.

Close #777