rbutil: Improve HiDPI support.

Replace the Rockbox logo with an svg version. Since the file size (i.e.
the page size in the svg) that isn't intended for use as icon we need to
enable scaling, and since scaling the label content doesn't keep the
aspect ratio we need to explicitly set the desired values.

Notably improves representation on HiDPI monitors. Now only the player
icons are still raster images.

Change-Id: I03216391a4b0ac982b16f5bec2b48c073369a3f6

rbutil/rbutilqt/rbutilqtfrm.ui

@@ -21,26 +21,35 @@
    <layout class="QGridLayout" name="gridLayout_3">
     <item row="0" column="0">
      <widget class="QLabel" name="logoLabel">
-      <property name="sizePolicy">
+      <property name="minimumSize">
-       <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
+       <size>
-        <horstretch>0</horstretch>
+        <width>200</width>
-        <verstretch>0</verstretch>
+        <height>62</height>
-       </sizepolicy>
+       </size>
+      </property>
+      <property name="maximumSize">
+       <size>
+        <width>200</width>
+        <height>62</height>
+       </size>
       </property>
       <property name="baseSize">
        <size>
-        <width>0</width>
+        <width>200</width>
-        <height>0</height>
+        <height>62</height>
        </size>
       </property>
       <property name="text">
        <string comment="Welcome to Rockbox Utility, the installation and housekeeping tool for Rockbox."/>
       </property>
       <property name="pixmap">
-       <pixmap resource="rbutilqt.qrc">:/icons/rblogo.png</pixmap>
+       <pixmap resource="rbutilqt.qrc">:/icons/rockbox-logo.svg</pixmap>
       </property>
       <property name="scaledContents">
-       <bool>false</bool>
+       <bool>true</bool>
+      </property>
+      <property name="alignment">
+       <set>Qt::AlignCenter</set>
       </property>
      </widget>
     </item>
@@ -473,7 +482,7 @@
   </action>
   <action name="actionComplete_Installation">
    <property name="icon">
-    <iconset resource="rbutilqt.qrc">
+    <iconset>
      <normaloff>:/icons/bootloader_btn.png</normaloff>:/icons/bootloader_btn.png</iconset>
    </property>
    <property name="text">
@@ -482,7 +491,7 @@
   </action>
   <action name="actionSmall_Installation">
    <property name="icon">
-    <iconset resource="rbutilqt.qrc">
+    <iconset>
      <normaloff>:/icons/rbinstall_btn.png</normaloff>:/icons/rbinstall_btn.png</iconset>
    </property>
    <property name="text">
@@ -491,7 +500,7 @@
   </action>
   <action name="actionInstall_Bootloader">
    <property name="icon">
-    <iconset resource="rbutilqt.qrc">
+    <iconset>
      <normaloff>:/icons/bootloader_btn.png</normaloff>:/icons/bootloader_btn.png</iconset>
    </property>
    <property name="text">
@@ -500,7 +509,7 @@
   </action>
   <action name="actionInstall_Rockbox">
    <property name="icon">
-    <iconset resource="rbutilqt.qrc">
+    <iconset>
      <normaloff>:/icons/rbinstall_btn.png</normaloff>:/icons/rbinstall_btn.png</iconset>
    </property>
    <property name="text">
@@ -509,7 +518,7 @@
   </action>
   <action name="actionFonts_Package">
    <property name="icon">
-    <iconset resource="rbutilqt.qrc">
+    <iconset>
      <normaloff>:/icons/font_btn.png</normaloff>:/icons/font_btn.png</iconset>
    </property>
    <property name="text">