Add unittests target to the binary distribution (issue #1632)

- Move all tests from the top-level directory to tests/.
- Move files shared by cefclient and unittests to tests/shared/.
- Add a fused (single header/source file) version of gtest in
  tests/gtest/ with associated CMake configuration.
- Test-only headers are now exposed in include/test/. Unit test
  targets must define UNIT_TEST in order to access them.
- Replace usage of USING_CEF_SHARED with WRAPPING_CEF_SHARED for
  clarity (only the libcef_dll_wrapper target should define it).
- Remove the RENAME_DIRECTORY CMake macro which is no longer used.
- Remove C++11 usage from unittests sources for compatibility with
  the binary distribution configuration.
- Windows: Fix build errors due to chrome_elf.dll and imm32.lib
  missing from the CMake configuration.

tools/make_ctocpp_header.py

@@ -60,15 +60,15 @@ def make_ctocpp_header(header, clsname):
 
     if clientside:
         result += """
-#ifndef BUILDING_CEF_SHARED
-#pragma message("Warning: "__FILE__" may be accessed DLL-side only")
-#else  // BUILDING_CEF_SHARED
+#if !defined(BUILDING_CEF_SHARED)
+#error This file can be included DLL-side only
+#endif
 """
     else:
         result += """
-#ifndef USING_CEF_SHARED
-#pragma message("Warning: "__FILE__" may be accessed wrapper-side only")
-#else  // USING_CEF_SHARED
+#if !defined(WRAPPING_CEF_SHARED)
+#error This file can be included wrapper-side only
+#endif
 """
 
     # build the function body
@@ -110,11 +110,6 @@ def make_ctocpp_header(header, clsname):
     result +=   func_body
     result +=   '};\n\n'
 
-    if clientside:
-        result += '#endif  // BUILDING_CEF_SHARED\n'
-    else:
-        result += '#endif  // USING_CEF_SHARED\n'
-
     result += '#endif  // CEF_LIBCEF_DLL_CTOCPP_'+defname+'_CTOCPP_H_'
 
     return wrap_code(result)