During validation, don't fail for schema-files which lack a declared type and non-DDL statements

[srcshelton]

Currently, we assume that schema-files lacking a d{d,m,c}l element in their file-name are DDL, and then validate (and potentially fail the file) on this basis.

This is incorrect - if the file doesn't explicitly declare itself as DDL, we shouldn't treat it as such.

(Although we can still flag a non-fatal warning that files should have a specified type)

[srcshelton]

Fixed in b0fc123 on branch latest