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_cmake.py

@@ -33,13 +33,6 @@ def get_files_for_variable(cmake_path, variables, variable):
     new_paths = []
     paths = variables[variable]
     for path in paths:
-        if path[0] == '<':
-            # Skip gyp include variables
-            continue
-        if path.find('/test/') >= 0:
-            # Skip test files
-            continue
-
         abspath = os.path.join(cef_dir, path)
         newpath = normalize_path(os.path.relpath(abspath, cmake_dirname))
         new_paths.append(newpath)