SDL/OPENGL: added info about GLSL version
EMI: Allow nil X, Y and Z values in SetActorHead.

This fixes Deadeye Dave's animation in pop.
EMI: If the head joint name is empty, don't do head tracing.
Merge pull request #962 from Akz-/emi-head-fixes

EMI: Fix Deadeye Dave's head
DEVTOOLS: it's not needed add non source code files into mdvc project
DEVTOOLS: disable build MT32 with msvc
DEVTOOLS: no need link with GLU32 in msvc
DEVTOOLS: define needs to be commented out if empty
ALL: synced with ScummVM
DEVTOOLS: disable flac and ogg/vorbis in msvc projects
OPENGL: remove GLU leftovers
BASE: correct to official description
ALL: unify setupScreen() arguments type
SDL: added safeguard for clearOverlay() if overlay is closed
SDL: don't call error() inside setupScreen(), it will crash if debugger is used
GRIM: Implement the getDebugger API

This allows errors to be shown in the debugger
EMI: Implement projection shadows.
EMI: Calculate actor bounding box correctly.

This is necessary for Actor::shouldDrawShadow to behave correctly, but
could also affect collision detection.
EMI: Enable shadow sprites.
GRIM/EMI: Make Light and SetShadow structs instead of classes.