Embed the qbs documentation also when building with qbs

Task-number: QTCREATORBUG-13124
Change-Id: I214a92a03a6d0fa75c1cceca1909c68add09d2c8
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

doc/doc.qbs

 import qbs
+import qbs.File
 
 Project {
     name: "documentation"
@@ -52,4 +53,15 @@ Project {
             excludeFiles: [mainDocConfFile]
         }
     }
+
+    property string qbsBaseDir: project.sharedSourcesDir + "/qbs"
+    property bool qbsSubModuleExists: File.exists(qbsBaseDir + "/qbs.qbs")
+    Properties {
+        condition: qbsSubModuleExists
+
+        references: [qbsBaseDir + "/doc/doc.qbs"]
+
+        // The first entry is for overriding qbs' own qbsbuildconfig module.
+        qbsSearchPaths: [project.ide_source_tree + "/qbs", qbsBaseDir + "/qbs-resources"]
+    }
 }

qbs/modules/qbsbuildconfig/qbsbuildconfig.qbs

@@ -15,6 +15,9 @@ Module {
     property string pluginsInstallDir: qtc.ide_plugin_path
     property string appInstallDir: qtc.ide_bin_path
     property string libexecInstallDir: qtc.ide_libexec_path
+    property bool installHtml: false
+    property bool installQch: !qbs.targetOS.contains("macos")
+    property string docInstallDir: qtc.ide_doc_path
     property string relativeLibexecPath: FileInfo.relativePath('/' + appInstallDir,
                                                                '/' + libexecInstallDir)
     property string relativePluginsPath: FileInfo.relativePath('/' + appInstallDir,