- Use a CASE() macro to simplify the vtstr() code and eliminate hard-coded variant type values.
- Update the list of known variant types.
- If a variant type is unknown, print its numerical value.
- In variantstr(), hand off all the standard cases to vtstr(), instead of (partially) duplicating its code.

gdi32: Pass an lpDx array to the driver if the escapement is non-zero, so that the driver has access to the unrotated advance widths.

oleaut32/tests: Fix the EQ_DOUBLE() and EQ_FLOAT() macros so they work no matter how large the values to compare are.

Use them everywhere.