release 2.7.0

increase version to 2.7.0

fix default interleave value

The default value for interleave was wrongly set to 50.

Remove the value and take the devault from the default constructor instead of side channeling it from the json parser.

remove usage of cn_v7 if cn_v8 is enabled

OpenCL: auto tuning option

OpenCl: fix NVIDIA

Cleanup missing change from #2101

NVIDIA is using clang as device compiler so the reciprocal optimizations was disabled with #2104.

- re-enable optimized reciprocal calculation

Add an option to brute force intensity settings and lock in at the intensity with the highest hashrate.

- update decumentation of the `interleave` option to mention the side effect with `auto-tune`
- disable `interleave` auto adjustment if `auto-tune` is enabled
- jconf: add `auto-tune` as optional option

- fix broken compile: change used `ULL` to `UL` because `UL` is defined as 64bit
- fix memory copy to shared memory via vload8 (somehow it create wrong access)

add interleave documentation

OpenCL: auto config two threads per GPU

fix clamp implementation

The auto config generates for AMD devices now by default two threads per GPU.

- remove the savety 128MiB memory now only from the max available GPU memory not from the avaialble memory for one alloc call
- extend the memory documentation in amd.txt

Due to a wrong implementation clamp was not working.

- add image to describe interleave better
- add tuning description

OpenCL: opimize reciprocal calculation

Please add Cryptonight-Superfast

OpenCL: comp mode optimization

use for non clang (Rocm) OpenCL a optimized reciprocal calculation without lookup table.

Co-authored-by: SChernykh <sergey.v.chernykh@gmail.com>

Disable compatibility mode if intensity is a multiple of worksize. In that case enabled compaibility mode will only slow down the miner.

update currencies

OpenCL: thread interleaving

- `monero` - remove fork from cn-v7 to cn-v8
- remove dev pool fork from cn-v7 to cn-8

If two threads are using the same GPU device the start time of each hash round is optimized based on the average time needed to calculate a bunch of hashes.

This way to optimize the hash rate was first introduced by @SChernykh. This implementation based on the implementation in xmrig but differen in the details.

- introduce a new config option `interleave`
- implement thread interleaving

OpenCl: optimize strided index 1

OpenCL: add strided_index 3

Use `mul24` to speedup the scratchpad index calculation.

Co-authored-by: SChernykh <sergey.v.chernykh@gmail.com>

Add new striding index where the memory is chunked by the size of the work group (worksize).

Co-authored-by: SChernykh <sergey.v.chernykh@gmail.com>

OpenCL: cnv8 optimization

OpenCl: optimize cn-v8 div

AMD: use more 32bit operations

OpenCL reduce API overhead

small optimization for non cryptonight_v8 algorithms

OpenCL: optimize cn-heavy div

- optimize division

CUDA: reduce cn-v8 shared mem footprint