Tools for people envious of nvidia's blob driver.

Contents:

* docs:    plain-text documentation of the GPUs, nVidia binary driver, and
           the tools (in-sync HTML version at http://envytools.rtfd.org)
* envydis: Disassembler and assembler for various ISAs found on nvidia GPUs
* rnn:     Tools and libraries for rules-ng-ng XML register database format
* rnndb:   rnn database of nvidia MMIO registers, FIFO methods, and memory
           structures
* nvbios:  Tools to decode card description structures found in nvidia VBIOS
* vstream: Tools to decode and encode raw video bitstreams
* easm:    Utility code dealing with assembly language parsing & printing
* util:    Misc utility code shared between envytools modules
* nva:     Tools to directly access the GPU registers
* hwtest:  undocumented tool
* vdpow:   A tool aiding in VP3 reverse engineering
* nvapy:   undocumented tool
           (requires optional dependency python3)
* cupti_trace:
           tool for REing performance counters
           (requires optional dependency cudatoolkit)
* demmt:   undocumented tool
           (sandboxing requires optional dependency libseccomp)

The nva, hwtest and vdpow tools are built by default, but can be disabled,
for example

  NVA="no" HWTEST="no" VDPOW="no" ./envytools.SlackBuild

Note that if the nva tool is disabled, the hwtest and vdpow tools will
also be disabled.

Optional dependencies (see above): cudatoolkit, libseccomp, and python3