Fix MDL effect decoding and check allocations

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Fix MDL fadeout setting

Rescale player fadeout to 0x10000 range (from 0x8000), double fadeout
values from XM and IT loaders.

Note: it seems that GAL4 and IMF loaders are ignoring fadeout values,
      check this!

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Update changelog

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>