TINYGL: cleanup license headers
MYST3: Make sure the script for loops reach their bounds

Fixes slightly wrong gauge value for the voltaic valves puzzle
EMI: clamp specialty textures

The specialty textures which are used in the intro need to be clamped
to avoid dark lines between the tiles.
EMI: Check another bit in the mesh face flags to enable blending.

Bit 0x40000 in the mesh face flags (set only in the intro) should
enable blending, too. This fix lets the various screens of the intro
fade into each other.
GRIM: fixed entries of polygon creation
EMI: Fix segfault when cancelling a save.
EMI: Recalculate volume and balance for positioned sounds when the setup changes. Fixes #996
EMI: Adjust attenuation of sounds to match the original game better.
GRIM/EMI: Do not do 3D positioning for voices.
EMI: Fixed sound panning.
EMI: Remap volumes from the range 0-100 to the range 0-255 for the audio mixer.
EMI: Fixed implementation of UpdateSoundPosition.
Merge pull request #1023 from chkr-private/intro-fixes

Intro fixes
MYST3: Fix the inventory item count not being saved
TINYGL: Do not write to the depth buffer if depth test is disabled.
Merge pull request #1027 from Akz-/tinygl-depth-fix

TINYGL: Do not write to the depth buffer if depth test is disabled.
Merge pull request #1007 from Akz-/emi-sound-position

GRIM/EMI: Positional sound tweaks
Merge pull request #1025 from JoseJX/FixESCAtSave

EMI: Fix segfault when cancelling a save.
MATH: improve type support for viewport argument
AMIGAOS4: update cross build