Move the test strings into their own array and convert them to unicode

Move the test strings into their own array and convert them to unicode
using a for loop. This lets us later print the offending string when a
test fails.
Fix the MSVC compilation error (XXXe183) and warnings (put suffixes as
in 0L & 1.0F, signed/unsigned warnings, s/-2147483648/0x80000000L/).
Uncomment the DateFromStr tests and fill in the todo fields where
appropriate.
Define an NB_OLE_STRINGS macro and use it to make sure all the arrays
have the right number of fields.
In the *FromStr loops, fill the return field with a dummy value (42)
before calling the conversion function. This way a test no longer
depends on whether the previous test failed or not!
If a test is expected to fail, then retval is meaningless -> omit it
from the result arrays.
If a test actually fails or was expected to fail, then there is no
point in checking retval.
Improve error reporting.
Pass the printf-style format directly to ok, remove the unnecessary
sprintfs.