analyze: implement mechanism to ignore some file changes

scripts/slave/recipes/ios/try.expected/without_patch_failure.json

 [
   {
     "cmd": [
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/ios/host_info.py",
       "--json-file",
       "/path/to/tmp/json"
     ],
     "name": "host and tools info",
     "~followup_annotations": [
       "@@@STEP_TEXT@<br />OS X 1.2.3, Xcode 6.7.8 (5D342509a)@@@",
@@ skipping 225 matching lines @@
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "import sys; sys.exit(0)"
     ],
     "name": "analyze",
     "~followup_annotations": [
+      "@@@STEP_TEXT@Analyze disabled: matched exclusion@@@",
       "@@@STEP_LOG_LINE@excluded_files@foo.cc (regex = 'f.*')@@@",
       "@@@STEP_LOG_END@excluded_files@@@",
       "@@@STEP_LOG_LINE@analyze_details@{@@@",
       "@@@STEP_LOG_LINE@analyze_details@  \"additional_compile_targets\": [@@@",
       "@@@STEP_LOG_LINE@analyze_details@    \"All\", @@@",
       "@@@STEP_LOG_LINE@analyze_details@    \"fake tests\"@@@",
       "@@@STEP_LOG_LINE@analyze_details@  ], @@@",
       "@@@STEP_LOG_LINE@analyze_details@  \"compile_targets\": [@@@",
       "@@@STEP_LOG_LINE@analyze_details@    \"All\", @@@",
       "@@@STEP_LOG_LINE@analyze_details@    \"fake tests\"@@@",
@@ skipping 146 matching lines @@
       "@@@STEP_FAILURE@@@",
       "@@@SET_BUILD_PROPERTY@failure_hash@\"5efacf6fa93d551b32a0023e205679db72d8ac1f\"@@@"
     ]
   },
   {
     "name": "$result",
     "reason": "Step('compile (without patch)') failed with return_code 1",
     "status_code": 1
   }
 ]