Bullet: update to 2.82 rev 2704

You probably don't want to look at the changes, it's huge, instead look at the individual commits.

This PR updates the bullet wrapper to version 2.82 rev 2704, but doesn't add the new functionality (like Featherstone and MLCP). It only updates the existing functionality of the wrapper with the bug fixes of 2.82.

It also includes some additional changes I had pending, closes #826 closes #836 and closes #837.

Tested on win64 and android.

This PR is mostly to check the others builds on jenkins, therefor will merge myself. I will try to create the swig interface for the new functionality tomorrow.