EMI: Handling of invalid bone names

Two animations (guy_puton_cap, guy_holdstickystuff) contain bone names
which which don't match any joints. To avoid that the holding actor is
drawn with a wrong orientation, ingore the unknown bone names when
running the animations.

Skeleton::getJointNamed() will now return null for unknown names.
The original behaviour for Actor::getWorldPos and
Actor::getRotationQuat is kept.

This patch fixes the problem, that Guybrush is "lying down" once he
holds the bottle of glue.
EMI/GRIM: Fix rotation of attached actors

Use matrix multiplications to fix the rotation for attached actors:
- calculate the final transformation matrix recursively for attached
  actors (instead of using getWorldPos and getWorldRot)
- use a different order for building the quaternions out of the Euler
  angles
- changed handling of camera position (just apply the rotation of the
  camera, the (inverted) position of the camera and the position of the
  actor
- no functional changes for GRIM
- no changes for drawing in overworld

Code simplification for GRIM:
- no need to use _currentPos in calculations for GRIM since it is
always (0, 0, 0)

This fixes:
- the rotation of any items Guybrush is holding in his hands
- the handling of the pole when using the raft in the swamps
- getting the bananas with the banana picker
EMI: Fix position of attached actor

When attaching an actor to another one, set its local position
so that its final position (position of the parent actor + the
local position) remains the same as the final position before
it was attached.
EMI: Update shader for actors and sprites [OpenGLS]
Merge pull request #822 from chkr-private/item-drawing-fixes

EMI: Rotation of (attached) actors