Apparently we were reading packed booleans wrong the whole time
(whoops!) They are packed into *bytes*, oops... That is fixed now, and I
also expanded write support for packed booleans. It makes the assumption
that the byte is always at the end of the row, but I think that's OK for
now.
I also added a good test-case for this, the PhysicsGroup EXD. It has a
lot of rows, and some packed booleans thrown in. The columns also have
out-of-order column definitions (as in, their offsets don't increase in
order.)
Now we can re-create OpeningSystemDefine, and is added as a new test
case to test reading/writing string columns. This was actually quite
fun, it turns out that they like aligning the data sections to a 4-byte
boundary for some reason.
Expanding upon the EXH tests of this same data, we can successfully
write it back (hence why it's testdata now!) A lot of the writing logic
is specific for this EXD, but it's a start.
I'm an idiot, these row ids are here for a reason and are important for actually
reading Excel sheets. The API has changed to a read_row() function that takes a
row id, and I'll improve it before release.
Now it reads much more of the index file format, and tries to handle
index1/index2 differences more opaquely. I'm not yet happy with the API, it
needs a bit more work.
