One TCOs Loop points are controlling other TCOs play-head pos in piano-roll

Nobody has claimed this yet.

OS : winXP sp3
LMMS RC4.6493

**Issue description:**
If one TCO has a block of notes encapsulated in looppoint, other TCOs will not play from 0 pos. Trying to do so, look like the notes vanish, and there will be no output. The reason is that lmms is playing inside 1. TCO loop-points, and there is ofcause no notes there in TCO-2.
Because of the 'short-ness' of 2. TCO, lmms will only show 2-5 bar of TCO-2, and it will appear to be empty.

**Example :**
Attached zip-file : TCOLooppointsInfluencePlay.mmp

**Recreate :**
* Insert a TCO make 20 bars of random notes
* Make a loop from bar 10-20
* Activate this loop (make it green)
* Move this TCO to pos 30 in song-editor
* open a new TCO in song-editor at bar pos 0
* Insert one bar of notes
* press play

Reproduce the behavior with the attached TCOLooppointsInfluencePlay.mmp file using the listed song-editor steps, then trace how piano-roll TCO loop points affect playback of other TCOs. Done means a TCO placed at song position 0 plays its notes from position 0 even when another TCO has an active loop.

Written by the indexing model from the issue text.