Changes

Feeding gr through the arg list where need only in the CLUBB_core dir.
Note, that since some of the functions/subroutines in CLUBB_core are
used elsewhere throughout clubb, other parts of clubb such as a file
in SILHS, and a few in the outer layer of the source folder needed to be
updated in order to reflect the changes.
However, everything outside of the CLUBB_core directory still uses use
statements in order to use gr from grid class.
For ticket #886.
All changes are confirmed BFB identical.

Reverted changes to clubb_api. For #886

Replacing use gr statements with feeding gr throught the arg list.
This commit is for slight improvement to the script in order to
better adhere to the coding standard.
For ticket #886.
Results confirmed to be BFB identical.

Fixed spacing issue when adding in gr. BFB identical. For #886.