Improved binary decoding performance and other minor fixes.

[RedMser]

Performance boost from reflection changes:

• Perf_Load_Binary5 runs around 40 milliseconds faster
• Loading bigger binary DMX data (around 50MB) ran 3 seconds faster (from 19 seconds to 16 seconds)

EDIT: Similar changes might be possible here, since the TypeToId function calls IsDatamodelArrayType as well.