Fix #202, update cmake recipe

Prefer target-scope properties over directory scope where applicable

CMakeLists.txt

@@ -1,8 +1,5 @@
 project(CFE_SAMPLE_APP C)
 
-include_directories(fsw/mission_inc)
-include_directories(fsw/platform_inc)
-
 # Create the app module
 add_cfe_app(sample_app fsw/src/sample_app.c)
 
@@ -11,7 +8,12 @@ add_cfe_app(sample_app fsw/src/sample_app.c)
 add_cfe_app_dependency(sample_app sample_lib)
 
 # Add table
-add_cfe_tables(sampleAppTable fsw/tables/sample_app_tbl.c)
+add_cfe_tables(sample_app fsw/tables/sample_app_tbl.c)
+
+target_include_directories(sample_app PUBLIC
+  fsw/mission_inc
+  fsw/platform_inc
+)
 
 # If UT is enabled, then add the tests from the subdirectory
 # Note that this is an app, and therefore does not provide