Problem with includes in header-only version

[hverhelst]

Hi!

I am trying to include optim in my project, in particular using the header-only version. When including optim.hpp in my file, the following inclusions fail (i.e. the files are not found by my project).

optim/include/misc/optim_misc.hpp

Lines 24 to 28 in 5453f48

	// structs
	#include "misc/optim_structs.hpp"
	// trace
	#include "misc/optim_trace.hpp"

When I remove misc/ from these paths, everything works as it should. I am not sure whether this change will break the library in other places... Any clue?