Convert builtin help to reStructuredText source files

Run the convert-help.bash script to convert documentation:

 ./convert-help.bash "/path/to/CMake-build/bin"

Then remove it.

Modules/AddFileDependencies.cmake

@@ -1,6 +1,10 @@
-# - ADD_FILE_DEPENDENCIES(source_file depend_files...)
-# Adds the given files as dependencies to source_file
+#.rst:
+# AddFileDependencies
+# -------------------
 #
+# ADD_FILE_DEPENDENCIES(source_file depend_files...)
+#
+# Adds the given files as dependencies to source_file
 
 #=============================================================================
 # Copyright 2006-2009 Kitware, Inc.