Expose QFont enums to the meta object system

Qt Quick Controls 2 needs configurable and toolable fonts for the
upcoming image-based style. Exposing these enums to the meta object
system allows the font weights, styles, etc. being specified as
enum value string names.

Change-Id: I024793656dd1af3a47d4edb5e27563a13c3b4c08
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

src/gui/text/qfont.h

@@ -68,6 +68,7 @@ public:
         Monospace,
         Fantasy
     };
+    Q_ENUM(StyleHint)
 
     enum StyleStrategy {
         PreferDefault       = 0x0001,
@@ -92,6 +93,7 @@ public:
         PreferVerticalHinting       = 2,
         PreferFullHinting           = 3
     };
+    Q_ENUM(HintingPreference)
 
     // Mapping OpenType weight value.
     enum Weight {
@@ -105,12 +107,14 @@ public:
         ExtraBold = 81,  // 800
         Black    = 87    // 900
     };
+    Q_ENUM(Weight)
 
     enum Style {
         StyleNormal,
         StyleItalic,
         StyleOblique
     };
+    Q_ENUM(Style)
 
     enum Stretch {
         AnyStretch     =   0,
@@ -124,6 +128,7 @@ public:
         ExtraExpanded  = 150,
         UltraExpanded  = 200
     };
+    Q_ENUM(Stretch)
 
     enum Capitalization {
         MixedCase,
@@ -132,11 +137,13 @@ public:
         SmallCaps,
         Capitalize
     };
+    Q_ENUM(Capitalization)
 
     enum SpacingType {
         PercentageSpacing,
         AbsoluteSpacing
     };
+    Q_ENUM(SpacingType)
 
     enum ResolveProperties {
         FamilyResolved              = 0x0001,