Add notes about using CMake + Qt Creator.

Change-Id: Ib10cc0a407721d62b39628af858f14e749c94d22
Reviewed-on: https://code.wireshark.org/review/10237
Reviewed-by: Gerald Combs <gerald@wireshark.org>

README.cmake

@@ -60,6 +60,10 @@ Note 1:
   # Disable building an application bundle (Wireshark.app) on Mac OS X
   -DENABLE_APPLICATION_BUNDLE=OFF
 
+  # Qt Creator expects .cbp files when used with CMake.
+  -G "CodeBlocks - Unix Makefiles"
+  -G "CodeBlocks - NMake Makefiles"
+
 Note 2:
   After running cmake, you can always run "make help" to see
   a list of all possible make targets.

doc/README.qt

@@ -21,11 +21,16 @@ There are several ways of building the Qt UI:
 
    Open the top-level CMakeLists.txt within Qt Creator. It should ask you to
    choose a build location. Do so. It should then ask you to run CMake. Fill in
-   any desired build arguments (e.g. "-D CMAKE_BUILD_TYPE:STRING=Debug" or
-   "-D ENABLE_GTK3:BOOL=OFF") and click the "Run CMake" button. When that
+   any desired build arguments (e.g. "-D CMAKE_BUILD_TYPE=Debug" or
+   "-D ENABLE_GTK3=OFF") and click the "Run CMake" button. When that
    completes select "Build → Open Build and Run Kit Selector..." and make
    sure wireshark is selected.
 
+   Note that Qt Creator uses output created by the CodeBlocks generator. If
+   you run CMake outside of Qt Creator you should use the "CodeBlocks - Unix
+   Makefiles" or "CodeBlocks - NMake Makefiles" generators, otherwise Qt
+   Creator will prompt you to re-run CMake.
+
 2) CMake:
 
    Qt (BUILD_wireshark) is enabled by default. Use the "cmake" command to