Help: Populate tutorial guide text

Migrate tutorial text from individual `directions.txt` files to the main
tutorial document.  Add some comments to source code to provide anchors
for inclusion.

Help/guide/tutorial/Step7/CMakeLists.txt

@@ -3,7 +3,7 @@ project(Tutorial)
 
 set(CMAKE_CXX_STANDARD 14)
 
-# the version number.
+# set the version number
 set(Tutorial_VERSION_MAJOR 1)
 set(Tutorial_VERSION_MINOR 0)
 

Help/guide/tutorial/Step7/MathFunctions/CMakeLists.txt

@@ -25,5 +25,6 @@ target_include_directories(MathFunctions
                   ${CMAKE_CURRENT_BINARY_DIR}
           )
 
+# install rules
 install(TARGETS MathFunctions DESTINATION lib)
 install(FILES MathFunctions.h DESTINATION include)

Help/guide/tutorial/Step7/directions.txt

@@ -1,40 +0,0 @@
-# Building an Installer #
-
-Next suppose that we want to distribute our project to other people so that they
-can use it. We want to provide both binary and source distributions on a variety
-of platforms. This is a little different from the install we did previously in
-the Installing and Testing section (Step 4), where we were installing the
-binaries that we had built from the source code. In this example we will be
-building installation packages that support binary installations and package
-management features. To accomplish this we will use CPack to create platform
-specific installers. Specifically we need to add a few lines to the bottom of
-our top-level CMakeLists.txt file.
-
-  include(InstallRequiredSystemLibraries)
-  set(CPACK_RESOURCE_FILE_LICENSE "${CMAKE_CURRENT_SOURCE_DIR}/License.txt")
-  set(CPACK_PACKAGE_VERSION_MAJOR "${Tutorial_VERSION_MAJOR}")
-  set(CPACK_PACKAGE_VERSION_MINOR "${Tutorial_VERSION_MINOR}")
-  include(CPack)
-
-That is all there is to it. We start by including InstallRequiredSystemLibraries.
-This module will include any runtime libraries that are needed by the project
-for the current platform. Next we set some CPack variables to where we have
-stored the license and version information for this project. The version
-information makes use of the variables we set earlier in this tutorial. Finally
-we include the CPack module which will use these variables and some other
-properties of the system you are on to setup an installer.
-
-The next step is to build the project in the usual manner and then run CPack
-on it. To build a binary distribution you would run:
-
-  cpack
-
-To create a source distribution you would type:
-
-  cpack -C CPackSourceConfig.cmake
-
-Alternatively, run “make package” or right click the Package target and
-“Build Project” from an IDE.
-
-Run the installer executable found  in the binary directory. Then run the
-installed executable and verify that it works.

Help/guide/tutorial/Step7/tutorial.cxx

@@ -5,6 +5,7 @@
 
 #include "TutorialConfig.h"
 
+// should we include the MathFunctions header?
 #ifdef USE_MYMATH
 #  include "MathFunctions.h"
 #endif
@@ -12,6 +13,7 @@
 int main(int argc, char* argv[])
 {
   if (argc < 2) {
+    // report version
     std::cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "."
               << Tutorial_VERSION_MINOR << std::endl;
     std::cout << "Usage: " << argv[0] << " number" << std::endl;
@@ -20,6 +22,7 @@ int main(int argc, char* argv[])
 
   double inputValue = std::stod(argv[1]);
 
+  // which square root function should we use?
 #ifdef USE_MYMATH
   double outputValue = mysqrt(inputValue);
 #else