* Cleaned BenchmarkCoreObject target to inherit all its build settings

* Turned on few Clang-specific warnings about implicit conversions in all targets

* Added -Wextra to all targets except TestCoreObject and BenchmarkCoreObject

* Turned on ARC by default (BasicPersistence still uses manual memory management)


git-svn-id: svn://svn.gna.org/svn/etoile/trunk/Etoile/Frameworks/CoreObject@9913 7b3f36aa-e6db-49c1-8b4c-66eac1997e64