Make the ICO image format a configurable feature

... including a [-no]-ico command line option.

Change-Id: I3cb13d2be72b512f72f8dcdb9de72e7a99e36e47
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

config_help.txt

@@ -274,6 +274,7 @@ Gui, printing, widget options:
 
   Image formats:
     -gif ............... Enable reading support for GIF [auto]
+    -ico ............... Enable support for ICO [yes]
     -libpng ............ Select used libpng [system/qt/no]
     -libjpeg ........... Select used libjpeg [system/qt/no]
 

configure.json

@@ -99,6 +99,7 @@
             "harfbuzz": { "type": "enum", "values": [ "no", "qt", "system" ] },
             "headersclean": "boolean",
             "host-option": "string",
+            "ico": "boolean",
             "iconv": { "type": "enum", "values": [ "no", "yes", "posix", "sun", "gnu" ] },
             "icu": "boolean",
             "imf": { "type": "boolean", "name": "qqnx_imf" },
@@ -2022,6 +2023,10 @@
             "condition": "features.png && libs.libpng",
             "output": [ "publicQtConfig" ]
         },
+        "ico": {
+            "description": "ICO",
+            "output": [ "feature" ]
+        },
         "system-zlib": {
             "description": "Using system zlib",
             "condition": "config.darwin || libs.zlib",
@@ -2766,7 +2771,7 @@ Please apply the patch corresponding to your Standard Library vendor, found in
                 {
                     "section": "Image formats",
                     "entries": [
-                        "gif", "jpeg", "system-jpeg", "png", "system-png"
+                        "gif", "ico", "jpeg", "system-jpeg", "png", "system-png"
                     ]
                 },
                 {

src/plugins/imageformats/imageformats.pro

@@ -1,5 +1,5 @@
 TEMPLATE = subdirs
 
-!contains(QT_CONFIG, no-ico):SUBDIRS += ico
+contains(QT_CONFIG, ico): SUBDIRS += ico
 contains(QT_CONFIG, jpeg): SUBDIRS += jpeg
 contains(QT_CONFIG, gif): SUBDIRS += gif