fix broken pool option overwrite via CLI

Correct link to README.md

fix #340

With #90 the option to overwrite the pool settings via CLI options is broken.

This pull request will allow to overwrite the options of the pool with the highest weighting.

Clean up the x-mas tree

Make k unsigned.

Clean up the x-mas tree

Right align hashrate report to six characters

[docs] Explicitly linked to an implied location

I expect that link is something that would be easily lost if another item is added.

optimize aes round command queue

add AMD scratchpad indexing option

fix Releases link

unroll AES round by hand to help the compiler to optimize the command queue

Change the default for strided index. Th euser feedback shows that strided_index = true will give a view hashes more per second.

Allow to change the indexing used to address the hash scratchpad memory.

- add option `strided_index` for each gpu

add environment variable `XMRSTAK_NOWIT`

- add documentation
- add environment variable `XMRSTAK_NOWAIT`

experimental warning: portable binaries

Really fixing incorrect Releases URL in README.md#Download

add warning that portable binaries are experimental

:)

Add custom message for dev -> user pool switch

Add custom message for dev -> user pool switch

update windows build documentation

fix CMake 

add hint that the new compiled xmr-stak-dep must be used for the new VS tool chain

- remove all `"${VARNAME}` usages in if conditions
- increase cmake minimum version to 3.1 to have the new behavior of [CMP0054](https://cmake.org/cmake/help/v3.1/policy/CMP0054.html)

- fix wrong compare for HWLOC not found
- remove usage of microhttpd variable if microhttpd is disabled

Adding Dockerfile and fixing build_xmr-stak_docker script

Fixed incorrect Releases URL in README.md#Download

fix CUDA launch bounds usage

fix auto suggestion for low end devices 

fix #191

lauch bounds must be placed before the return type but after the template paramater

Add compilation instructions for MacOS

Fix for AMD GPU detection on MacOS X