Move subsurface-core to core and qt-mobile to mobile-widgets

Having subsurface-core as a directory name really messes with
autocomplete and is obviously redundant. Simmilarly, qt-mobile caused an
autocomplete conflict and also was inconsistent with the desktop-widget
name for the directory containing the "other" UI.

And while cleaning up the resulting change in the path name for include
files, I decided to clean up those even more to make them consistent
overall.

This could have been handled in more commits, but since this requires a
make clean before the build, it seemed more sensible to do it all in one.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

mobile-widgets/qml/SubsurfaceButton.qml

@@ -0,0 +1,26 @@
+import QtQuick 2.5
+import QtQuick.Controls 1.2
+import QtQuick.Controls.Styles 1.2
+import org.kde.kirigami 1.0 as Kirigami
+
+Button {
+	style: ButtonStyle {
+		padding {
+			top: Kirigami.Units.smallSpacing * 2
+			left: Kirigami.Units.smallSpacing * 4
+			right: Kirigami.Units.smallSpacing * 4
+			bottom: Kirigami.Units.smallSpacing * 2
+		}
+		background: Rectangle {
+			border.width: 1
+			radius: height / 3
+			color: control.pressed ? subsurfaceTheme.shadedColor : subsurfaceTheme.accentColor
+		}
+		label: Text{
+			text: control.text
+			color: subsurfaceTheme.accentTextColor
+			verticalAlignment: Text.AlignVCenter
+			horizontalAlignment: Text.AlignHCenter
+		}
+	}
+}