added scrollwheel support for GLFW

implemented scroll events based on the already provided scroll_cb in
ofAppGLFWWindow.cpp
fixed inconsistent indentation
deleted subproject in devApps
Merge branch 'feature-scrollwheel-support' of https://github.com/fakob/openFrameworks into feature-scroll

Conflicts:
	libs/openFrameworks/app/ofAppRunner.cpp
	libs/openFrameworks/events/ofEvents.h
scroll event to float