Support for CONTIGUOUS and CODIMENSION statements in F2008

[rupertford]

Support has been added for both CODIMENSION and CONTIGUOUS as attributes but not as statements, see R531 and R533 respectively in the F2008 spec. These would need to be added to R212 other-specification-stmt noting the name change from F2003 where it was specification-stmt. It would be worth changing the name as the new name is also used in F2018. Also note there appears to be an error in the spec as CONTIGUOUS is not added anywhere but it seems clear that it should also be in other-specification-stmt.