added new sub-doc tests for multidimensional arrays

added these tests, they are currently failing
fixed issue with null/undefined values in arrays

There was an error where if there was an array of the form
[x,y, null, null, z], it would not properly get cast. This fix
corrects that error.
fixed errors in subdocument tests

This fixes a couple bugs that were in the subdocument tests for
multidimensional fields
major bug fixes for multidimensional subdocs

this contains significant bug fixes for multidimensional
subdocuments. This now passes all of the multidimensional document
test.
forgot to remove .only() from test cases, couple errors to deal with on tests
small fix in the schema array

needed to move a check for the type until after the first if
statement. This had already been like that, but I changed it at
some point, unclear why.
fixed an issue with casting for mixed types
bug fixes for multidimensional arrays

couple small bug fixes, now passing all tests except for 1 test in
the versioning test suite. Not sure what is going on there