More defines needed to build on Windows
Sort exports in the .def file

Makes it easier to search through.
Don't export symbols from ICU

This is causing errors. I suspect we actually do need to export them and need to figure out the cause of the errors.
Don't export base's kEventLogId

Trying to do so causes errors. Not sure why yet.
Turn off incremental linking

This lets us see all the linker errors at once, and gets rid of a warning about the module being too big to link incrementally.
Turn off the custom allocator

This was causing linker errors due to using two versions of the CRT (Release for the allocator, Debug for everything else).