Overview of hardware acceleration support

[securitykernel]

I'd like to see an overview of all hardware acceleration features utilized by Botan, on which platforms they are supported, whether they are enabled by default and how to enable/disable them, how to find out if they are supported on a specific system, and probably also a rough estimate on the factor of performance gain when using them. The best location of such an overview probably is the handbook. I'd also think hardware random number generators should be part of this overview, so I am not sure whether "hardware acceleration" would be the right headline.

None of the major crypto libraries currently provide such an overview, so that would also set Botan apart.