Adds doc on the --help flag.

wiki/GoogleTestAdvancedGuide.wiki

@@ -730,6 +730,7 @@ _Availability_: Linux, Windows, Mac.
 =  Sharing Resources Between Tests in the Same Test Case  =
 
 
+
 Google Test creates a new test fixture object for each test in order to make
 tests independent and easier to debug. However, sometimes tests use resources
 that are expensive to set up, making the one-copy-per-test model prohibitively
@@ -1279,6 +1280,7 @@ _Note:_ Google Test is designed with threads in mind.  Once the
 synchronization primitives in `<gtest/internal/gtest-port.h>` have
 been implemented, Google Test will become thread-safe, meaning that
 you can then use assertions in multiple threads concurrently.  Before
+
 that, however, Google Test only supports single-threaded usage.  Once
 thread-safe, `EXPECT_FATAL_FAILURE()` and `EXPECT_NONFATAL_FAILURE()`
 will capture failures in the current thread only. If _statement_
@@ -1339,6 +1341,10 @@ them directly and affect their behavior via the following environment variables
 and/or command line flags. For the flags to work, your programs must call
 `testing::InitGoogleTest()` before calling `RUN_ALL_TESTS()`.
 
+To see a list of supported flags and their usage, please run your test
+program with the `--help` flag.  You can also use `-h`, `-?`, or `/?`
+for short.  This feature is added in version 1.3.0.
+
 If an option is specified both by an environment variable and by a
 flag, the latter takes precedence.  Most of the options can also be
 set/read in code: to access the value of command line flag
@@ -1478,6 +1484,7 @@ _Availability:_ Linux, Windows, Mac.
 
 == Controlling Test Output ==
 
+
 === Colored Terminal Output ===
 
 Google Test can use colors in its terminal output to make it easier to spot