Icon in menu

- 48px icon in the project menu fixed to the correct 24px one.
[JENKINS-22213] Broken backward compatibility with version 1.14

- Build action's readResolve() computes health report percentage which internally calls getPreviousAction(). It probably confuses the deserializer which results in StackOverflowError exception. The computation replaced by hardcoded value 100% to fix the issue.
- Relative jelly include <st:include page="../CppcheckBuildAction/statistics.jelly"/> works (probably) only in mvn hpi:run, absolute <st:include page="/org/jenkinsci/plugins/cppcheck/CppcheckBuildAction/statistics.jelly"/> is used instead.