Rework themes to easily use light/dark palette, using only different icons

- Renamed themes:
  - "colorful" to "default" and "colorful_dark" to "default_dark"
  - "default" to "monochrome" and "default_dark" to "monochrome_dark"
  - "colorful_midnight_blue" to "qdarkstyle_midnight_blue"
  - "qdarkstyle_midnight_blue" to "qdarkstyle_midnight_blue_monochrome"
  - qdarkstyle is renamed from "Dark" to "Mine Shaft" in the UI
- default and monochrome themes all use the same qss stylesheet
- Remove the ability to select "default_dark" directly
- Add "qdarkstyle_monochrome" theme
- Remove duplicated icon files

dist/qt_themes/default/default.qrc

@@ -1,26 +1,40 @@
 <!--
-SPDX-FileCopyrightText: 2018 yuzu Emulator Project
+SPDX-FileCopyrightText: 2019 yuzu Emulator Project
 SPDX-License-Identifier: GPL-2.0-or-later
 -->
 
 <RCC>
+    <!-- Default style -->
+    <qresource prefix="default">
+        <file>style.qss</file>
+    </qresource>
+
+    <!-- Default icons -->
     <qresource prefix="icons/default">
-        <!-- "colorful" is now the default theme, add new icons there -->
         <file alias="index.theme">icons/index.theme</file>
         <file alias="16x16/connected.png">icons/16x16/connected.png</file>
         <file alias="16x16/connected_notification.png">icons/16x16/connected_notification.png</file>
         <file alias="16x16/disconnected.png">icons/16x16/disconnected.png</file>
+        <file alias="16x16/failed.png">icons/16x16/failed.png</file>
+        <file alias="16x16/info.png">icons/16x16/info.png</file>
         <file alias="16x16/lock.png">icons/16x16/lock.png</file>
+        <file alias="16x16/sync.png">icons/16x16/sync.png</file>
+        <file alias="16x16/view-refresh.png">icons/16x16/view-refresh.png</file>
         <file alias="48x48/bad_folder.png">icons/48x48/bad_folder.png</file>
         <file alias="48x48/chip.png">icons/48x48/chip.png</file>
         <file alias="48x48/folder.png">icons/48x48/folder.png</file>
         <file alias="48x48/list-add.png">icons/48x48/list-add.png</file>
+        <file alias="48x48/no_avatar.png">icons/48x48/no_avatar.png</file>
         <file alias="48x48/sd_card.png">icons/48x48/sd_card.png</file>
         <file alias="48x48/star.png">icons/48x48/star.png</file>
         <file alias="256x256/plus_folder.png">icons/256x256/plus_folder.png</file>
         <file alias="256x256/yuzu.png">icons/256x256/yuzu.png</file>
     </qresource>
-    <qresource prefix="default">
-        <file>style.qss</file>
+
+    <!-- Dark variant icons -->
+    <qresource prefix="icons/default_dark">
+        <file alias="index.theme">../default_dark/icons/index.theme</file>
+        <file alias="16x16/lock.png">../default_dark/icons/16x16/lock.png</file>
+        <file alias="16x16/view-refresh.png">../default_dark/icons/16x16/view-refresh.png</file>
     </qresource>
 </RCC>

dist/qt_themes/default/icons/index.theme

@@ -1,7 +1,6 @@
 [Icon Theme]
 Name=default
-Comment=default theme
-Inherits=colorful
+Comment=Colorful theme
 Directories=16x16,48x48,256x256
  
 [16x16]
@@ -9,6 +8,6 @@ Size=16
 
 [48x48]
 Size=48
- 
+
 [256x256]
 Size=256

dist/qt_themes/default/style.qss

@@ -25,7 +25,7 @@ QPushButton#TogglableStatusBarButton {
 }
 
 QPushButton#TogglableStatusBarButton:checked {
-    color: #000000;
+    color: palette(text);
 }
 
 QPushButton#TogglableStatusBarButton:hover {
@@ -52,6 +52,10 @@ QPushButton#RendererStatusBarButton:!checked {
     color: #0066ff;
 }
 
+QPushButton#RendererStatusBarButton:!checked[dark=true] {
+    color: #00ccdd;
+}
+
 QPushButton#GPUStatusBarButton {
     color: #656565;
     border: 1px solid transparent;
@@ -68,13 +72,21 @@ QPushButton#GPUStatusBarButton:checked {
     color: #b06020;
 }
 
+QPushButton#GPUStatusBarButton:checked[dark=true] {
+    color: #ff8040;
+}
+
 QPushButton#GPUStatusBarButton:!checked {
     color: #109010;
 }
 
+QPushButton#GPUStatusBarButton:!checked[dark=true] {
+    color: #40dd40;
+}
+
 QPushButton#DockingStatusBarButton {
     min-width: 0px;
-    color: #000000;
+    color: palette(text);
     border: 1px solid transparent;
     background-color: transparent;
     padding: 0px 3px 0px 3px;
@@ -134,10 +146,6 @@ QWidget#connectedControllers {
     background: transparent;
 }
 
-QWidget#closeButtons {
-    background: transparent;
-}
-
 QWidget#playersSupported,
 QWidget#controllersSupported,
 QWidget#controllerSupported1,
@@ -386,7 +394,7 @@ QStackedWidget#stackedDialog QTextBrowser QScrollBar::vertical {
     border-radius: 4px;
 }
 
-QStackedWidget#stackedDialog QTextBrowser QScrollBar::horizoncal {
+QStackedWidget#stackedDialog QTextBrowser QScrollBar::horizontal {
     background: #cdcdcd;
     height: 15px;
     margin: 3px 15px 3px 15px;