Rename .h files to .hpp

Changes name to all .h files to .hpp. Additionally all #include directives
are changed to point to .hpp headers.
Merge pull request #55 from nfprojects/convert_h_to_hpp

Rename .h files to .hpp
Merge branch 'devel' into threadpool

Conflicts:
	nfEngine/nfCommon/ThreadPool.cpp
	nfEngine/nfCommon/ThreadPool.hpp
	nfEngine/nfCommon/nfCommon.vcxproj
	nfEngine/nfCommon/nfCommon.vcxproj.filters
	nfEngine/nfCommonTest/ThreadPoolTest.cpp
	nfEngine/nfCommonTest/nfCommonTest.vcxproj
	nfEngine/nfCommonTest/nfCommonTest.vcxproj.filters
	nfEngine/nfCore/Engine.hpp
	nfEngine/nfCore/PhysicsWorld.hpp
	nfEngine/nfCore/ResourcesManager.hpp
	nfEngine/nfCore/SceneManager.hpp
[CRFIX]