Allow for cuda::device_vector to be converted to host vector

compile fix

Update changelog

Make cuda::device_vector more versatile

Simplify

Reactivate two debug prints that got deleted

Remove some debug prints

fix WIN32

Wrap cuda/hip calls into macro calls

Newer boost has removed the "system" library

Layout fix

Remove interval::invalidate() again

Add box4 typedefs specializing interval<T>

Add interval::invalidate()

Make new version v0.6.1