Debugger: Add a README to help with dumper command line use

Not exactly the intended use, and whence not part of the docs.

Change-Id: I622c3aef637700c895e37f79cc6ffac7b2cd5205
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>
Reviewed-by: hjk <hjk121@nokiamail.com>

share/qtcreator/debugger/README.txt

@@ -0,0 +1,68 @@
+
+While the primary intention of this pretty printing implementation is
+to provide what Qt Creator needs, it can be used in a plain commandline
+GDB session, too.
+
+With
+
+        python sys.path.insert(1, '<path/to/qtcreator>/share/qtcreator/debugger/')
+        python from gdbbridge import *
+
+in .gdbinit there is a new "GDB command", called "pp".
+
+With code like
+
+        int main(int argc, char *argv[])
+        {
+            QString ss = "Hello";
+            QApplication app(argc, argv);
+            app.setObjectName(ss);
+            // break here
+        }
+
+    the "pp" command can be used as follows:
+
+    (gdb) pp app
+    app =
+       [
+          <QGuiApplication> = {"Hello"}
+          staticMetaObject = <QMetaObject> = {""}
+          [parent] = <QObject *> = {"0x0"}
+          [children] = <QObjectList> = {"<3 items>"}
+          [properties] = "<>0 items>"
+          [methods] = "<6 items>"
+          [signals] = "<1 items>"
+       ],<QApplication> = {"Hello"}
+
+    (gdb) pp app [properties],[children]
+    app =
+       [
+          <QGuiApplication> = {"Hello"}
+          staticMetaObject = <QMetaObject> = {""}
+          [parent] = <QObject *> = {"0x0"}
+          [children] = [
+             <QObject> = {""}
+             <QObject> = {""}
+             <QObject> = {"fusion"}
+          ],<QObjectList> = {"<3 items>"}
+          [properties] = [
+             windowIcon = <QVariant (QIcon)> = {""}
+             cursorFlashTime = <QVariant (int)> = {"1000"}
+             doubleClickInterval = <QVariant (int)> = {"400"}
+             keyboardInputInterval = <QVariant (int)> = {"400"}
+             wheelScrollLines = <QVariant (int)> = {"3"}
+             globalStrut = <QVariant (QSize)> = {"(0, 0)"}
+             startDragTime = <QVariant (int)> = {"500"}
+             startDragDistance = <QVariant (int)> = {"10"}
+             styleSheet = <QVariant (QString)> = {""}
+             autoSipEnabled = <QVariant (bool)> = {"true"}
+          ],"<10 items>"
+          [methods] = "<6 items>"
+          [signals] = "<1 items>"
+       ],<QApplication> = {"Hello"}
+
+    (gdb) pp ss
+    ss =
+       <QString> = {"Hello"}
+
+