fix intents and variable types in interfaces

[rwirth]

Fix a few intents, array-ness, and type of arguments in the nf and nf90 interfaces.

Fixes #417

[CLAassistant]

All committers have signed the CLA.

[skosukhin]

It might make sense to fix fortran/nf_nc4.F90 as well:

diff --git a/fortran/nf_nc4.F90 b/fortran/nf_nc4.F90
index 30ea9ee..a1b58f2 100755
--- a/fortran/nf_nc4.F90
+++ b/fortran/nf_nc4.F90
@@ -566,11 +566,11 @@

  Implicit NONE

- Integer,          Intent(IN)    :: ncid, xtype, field_typeid, offset, ndims
- Character(LEN=*), Intent(IN)    :: name
- Integer,          Intent(INOUT) :: dim_sizes(*)
+ Integer,          Intent(IN) :: ncid, xtype, field_typeid, offset, ndims
+ Character(LEN=*), Intent(IN) :: name
+ Integer,          Intent(IN) :: dim_sizes(*)

- Integer                         :: status
+ Integer                      :: status

  Integer(C_INT)               :: cncid, cxtype, ctypeid, cndims, cstatus
  Integer(C_SIZE_T)            :: coffset
@@ -1370,10 +1370,10 @@

  Implicit NONE

- Integer, Intent(IN)    :: ncid, varid, contiguous
- Integer, Intent(INOUT) :: chunksizes(*)
+ Integer, Intent(IN) :: ncid, varid, contiguous
+ Integer, Intent(IN) :: chunksizes(*)

- Integer                :: status
+ Integer             :: status

  Integer(C_INT) :: cncid, cvarid, ccontiguous, cstat1, cstatus, &
                    cndims

[RobertPincus]

@WardF Any possibility of merging this PR? I collaborate with the group in which @rwirth and @skosukhin work and am happy for the support of the very strict NAG compiler. (It's also possible that these errors descend from my initial Fortran 90 interface for netCDF written in the late 1990s).

[WardF]

Thanks for the ping; I've been focused on the C PR backlog. Running tests now and will get merged.