Part of series to remove and clean-up GPU code.

- more consistent with spec.

- more spec compliant.
- closes #39 (github).

- spec compliant.
- closes #40 (github).

- spec compliant.
- closes #41 (github).

- not to shadow GASPI spec function with same name.
- closes #38 (github)

- closes #26 (github)

- to be able to run tests from anywhere
- closes #35 (github)

The reason for this is Fortran.

The previous value results in error.

Mostly on IB device:
- removal of unncessary members in dev ctx
- move dev info print to own function
- improve style and comments