Introduce a Qt-free JSON implementation

This is essentially QJson with Qt replaced by std:: features.

This is useful to have in circumstances where a Qt dependency
is undesirable, e.g. for the Qt Creator debugger protocol
implementation in our CDB extension.

Change-Id: Iec79c6b23b1e717ce1b6f4d38755287d1f479c13
Reviewed-by: David Schulz <david.schulz@theqtcompany.com>

src/shared/json/README.md

+This is QJson without Qt, to be used in circumstances
+where a Qt dependency is not desirable, such as
+qtcreatorcdbex.

src/shared/json/json.pri

+HEADERS += $$PWD/json.h
+SOURCES += $$PWD/json.cpp

src/shared/json/json.qbs

+import qbs
+
+StaticLibrary {
+    name: "qtcjson"
+    Depends { name: "cpp" }
+    cpp.cxxLanguageVersion: "c++11"
+    files: [
+        "json.cpp",
+        "json.h",
+    ]
+    Export {
+        Depends { name: "cpp" }
+        cpp.includePaths: [product.sourceDirectory]
+    }
+}

src/src.qbs

@@ -45,6 +45,7 @@ Project {
             qbsBaseDir + "/src/plugins/plugins.qbs",
             qbsBaseDir + "/share/share.qbs",
             qbsBaseDir + "/src/app/apps.qbs",
+            project.sharedSourcesDir + "/json",
         ]
     }
 }

tests/auto/auto.pro

@@ -13,6 +13,7 @@ SUBDIRS += \
     profilewriter \
     treeviewfind \
     qtcprocess \
+    json \
     utils \
     filesearch \
     sdktool \

tests/auto/auto.qbs

@@ -14,6 +14,7 @@ Project {
         "externaltool/externaltool.qbs",
         "filesearch/filesearch.qbs",
         "generichighlighter/generichighlighter.qbs",
+        "json/json.qbs",
         "profilewriter/profilewriter.qbs",
         "qml/qml.qbs",
         "qtcprocess/qtcprocess.qbs",

tests/auto/json/bom.json

+{
+    "info-version": "1.0"
+}

tests/auto/json/json.pro

+TARGET = tst_json
+QT = core testlib
+CONFIG -= app_bundle
+CONFIG += testcase
+
+TESTDATA += test.json test.bjson test3.json test2.json bom.json
+
+INCLUDEPATH += ../../../src/shared/json
+
+DEFINES += QT_NO_CAST_TO_ASCII QT_NO_CAST_FROM_ASCII
+
+include(../../../src/shared/json/json.pri)
+SOURCES += tst_json.cpp

tests/auto/json/test2.json

+{ "foo": ["ab"] }