Remove redundant envelope end test

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

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Fix IT toneporta in first note

Jan Engelhardt reports that libxmp-4.3.0 fails to play an IT note with a
tone portamento effect, and that note is the first note of that channel.
So, if we don't have a previous note, ignore the tone portamento.

Module: RAVE-n - Oxygen 4 2001.it, channel 28

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Fix MOD note range enforcing

Jason Gibson reports an off-key note in Jason Thomale's Apathy.mod. This
module was incorrectly detected as a Noisetracker module, even if a note
outside of the Noise/Sound/Protracker range was used. In this case, don't
detect as an Amiga tracker (use unknown tracker instead) an don't enforce
amiga limits.

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
[test] Add mod loader note range test

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