Merge branch 'build_cmake' of https://github.com/TcT2k/wxWidgets

Add CMake-based build system.

Merge the original branch without any changes except for resolving the
conflict due to moving the contents of .travis.yml to a separate file by
propagating the changes done in this file since then to the new script
and rerunning ./build/update-setup-h and ./build/cmake/update_files.py
to update the file lists changed in the meanwhile.

Closes https://github.com/wxWidgets/wxWidgets/pull/330

build/cmake/demos/CMakeLists.txt

@@ -0,0 +1,78 @@
+#############################################################################
+# Name:        build/cmake/demos/CMakeLists.txt
+# Purpose:     CMake script for demos
+# Author:      Tobias Taschner
+# Created:     2016-10-21
+# Copyright:   (c) 2016 wxWidgets development team
+# Licence:     wxWindows licence
+#############################################################################
+
+function(wx_add_demo name)
+    cmake_parse_arguments(DEMO "" "NAME" "DATA;LIBRARIES" ${ARGN})
+    if(NOT DEMO_NAME)
+        set(DEMO_NAME ${name})
+    endif()
+    wx_list_add_prefix(src_files
+        "${wxSOURCE_DIR}/demos/${name}/"
+        ${DEMO_UNPARSED_ARGUMENTS})
+    if(WIN32)
+        list(APPEND src_files ${wxSOURCE_DIR}/demos/${name}/${DEMO_NAME}.rc)
+    endif()
+    add_executable(${DEMO_NAME} WIN32 MACOSX_BUNDLE ${src_files})
+    if(DEMO_DATA)
+        # TODO: unify with data handling for samples
+        # TODO: handle data files differently for OS X bundles
+        # Copy data files to output directory
+        foreach(data_file ${DEMO_DATA})
+            list(APPEND cmds COMMAND ${CMAKE_COMMAND}
+                -E copy ${wxSOURCE_DIR}/demos/${name}/${data_file}
+                ${wxOUTPUT_DIR}/${data_file})
+        endforeach()
+        add_custom_command(
+            TARGET ${DEMO_NAME} ${cmds}
+            COMMENT "Copying demo data files...")
+    endif()
+    if(wxBUILD_SHARED)
+        target_compile_definitions(${DEMO_NAME} PRIVATE WXUSINGDLL)
+    endif()
+    target_link_libraries(${DEMO_NAME} core ${DEMO_LIBRARIES})
+    wx_set_common_target_properties(${DEMO_NAME})
+    set_target_properties(${DEMO_NAME} PROPERTIES FOLDER "Demos")
+endfunction()
+
+wx_add_demo(bombs
+    bombs.cpp
+    bombs1.cpp
+    game.cpp
+    )
+wx_add_demo(forty
+    forty.cpp
+    canvas.cpp
+    card.cpp
+    game.cpp
+    pile.cpp
+    playerdg.cpp
+    scoredg.cpp
+    scorefil.cpp
+    DATA
+        about.htm
+    LIBRARIES
+        html adv xml
+    )
+wx_add_demo(fractal fractal.cpp)
+wx_add_demo(life
+    life.cpp
+    dialogs.cpp
+    game.cpp
+    reader.cpp
+    DATA
+        breeder.lif
+    )
+wx_add_demo(poem wxpoem.cpp
+    DATA
+        wxpoem.txt wxpoem.dat wxpoem.idx
+    LIBRARIES
+        html
+    NAME
+        wxpoem
+    )