Clean up CMock makefiles and add coverage filtering (#523)

* Cleanup Makefiles

* Add lcovrc configuration file

* Add CMock test build directory to .gitignore

* Add callgraph.py and filtercov.py scripts

* Cleanup list Makefile and update list_utest.c with coverage tags

* Add information about coverage filtering and running single test cases

* Remove -fprofile-exclude-files for compatibility with older versions of gcc.
Fix line endings (change to unix style)

* Lint callgraph.py and filtercov.py. Print and error when no target functions are defined.

* Indent with spaces when possible

* Replace tabs with spaces and enable .RECIPEPREFIX

* Add fake_port.h and related portmacro.h changes

* Fix list makefile when bin directory is not available

* Clean up grouped rules

* Update makesfile.. Add "two_tests" example dir

* Fix memory checker error

* Move common makefile items to subdir.mk and testdir.mk includes

* Update core_checker.py exclusions

* Remove line from portmacro.h that doesn't match core_checker.py

.github/scripts/core_checker.py

@@ -175,6 +175,7 @@ FREERTOS_IGNORED_EXTENSIONS = [
     '.properties',
     '.ps1',
     '.ptf',
+    '.py',
     '.r79',
     '.rapp',
     '.rc',
@@ -263,7 +264,8 @@ FREERTOS_IGNORED_FILES = [
     'mbedtls_config.h',
     'requirements.txt',
     'run-cbmc-proofs.py',
-    '.editorconfig'
+    '.editorconfig',
+    'lcovrc'
 ]
 
 FREERTOS_HEADER = [