[IMPROVE] move main structs to global

TODO: do it for cuda (gpu verion has been broken)

Signed-off-by: Anastasia Lyupa <anastasiya.lyupa@gmail.com>
[IMPROVE] memory allocation in Newton's method
[IMPROVE] update cuda version

- use global vars
- update assign_roS_kernel_nr and assign_roS_kernel
according to cpu version

TODO: fix DevBuffer

Signed-off-by: Anastasia Lyupa <anastasiya.lyupa@gmail.com>