Distorted Android

Another attempt at fixing tthings on early Qualcomm OpenGL ES 3.0 drivers.

The previous version does not work on Adreno 405 driver V@100, present for example in a Asus ZenPad 8.
Revert the packed 'ivec2' UBO in the vertex shader back to a 'std140' ivec4. This comes at a price if bumping into the bug on Qualcomm driver version 331 on Adreno 308 - i.e. Samsung Galaxy J4+ again....

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Make the 'Component Associations' UBO (on most devices) twice smaller -
use the 'packed' layout and 'ivec2' in place of 'ivec4'.

This forces us to dynamically probe the 'Stride' - number of 4-byte entities that the UBO's 'ivec4' takes - and correct the already-constructed UniformBlockAssociation objects in case this turns out to be different than the expected 2, i.e. tightly-packed....

Add a new API DistortedEffects.exists(long id)

Make per-component centers optional, controlled by API MeshBase.setUseCenters()

Bugfixes as a result of the Samsung Galaxy J4+ investigation:

1) By default, switch off transform feedback in the main program.
Create a new API 'needTransformFeedback()' to call if someone still needs TF in the main program.
2) lower the default max number of vertex effects to 30....

Progress with Megaminx.