add option `unroll` for OpenCL to allow better tuning the main POW kernel.

Create a special pass for NVIDIA GPUs to load memory chunks first into the shared memory.

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

- use shared memory to exchange

implement `cryptonight_v8`

- implement cryptonight_v8
- update auto adjust to fit the special requirements of `cryptonight_v8`
- add fast math integer implementation for `sqrt`, `reciprocal`  and `division`

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

Add support for single hash cryptonight_v8.

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

- rmeove currency `monero7`
- introduce `cryptonight_v8` and `monero8`

During the initialization of the compile parameter for OpenCL it could be that the
fixed size buffer is to small. To avoid this we are now using `std::string`.
There is no problem by using `std::string` because this part of code is not perfromance critical.

If the first bit of the nonce is `1` (this is very often if we use a nicehash pool)
than it could be that some OpenCL implementations handle the 64bit representation of the 32bit
nonce on the device side as signed integer.
During a right bitshift we pull wrong ones from the wrong higher part of the 64bit
nonce representation into the 32bit part of the nonce.
The result will be that the computed share is invalid.

- explicit cast the nonce on the device to `uint` to avoid any side effects

Avoid that a OpenCL binary from the cache is used if the driver or xmr-stak version has changed.

There is a copy past mistake tha tthe type of the variable `memChunk` is not tested.

xmr-stak has several implementations for multi hash per thread.
The results into 3 intepedent implementations.
Each time the algorithm must be changed the possibility to introduce errors is very large.

- unify the different cryptonight CPU implementations
- simplify the function selection array to find the specilized cryptonight implementation
- add a intermediat pointer to access the large state (similar to the old multi hash implementation)

As side effect this change increases the speed of the single and multi hash algorithm.

The most algorithm currently are not checked in the cpu self test function.

- add hash for each algorithm

Improve the grammar of the Dev donation setting.

The coint type was set to a fixed value in one of the last released and has no meaning since we support many cryptonight coins.

- remove cointtype from version.cpp

OpenCl 1.2.is not allowing the subscript operator on buildin vector types.

fix: use `.sX` to access vector components

5% more hash per second

- add cryptonight_heavy derivate cryptonight_bittube2
- add coin bittube
- remove coin ipbc because this coin is now called bittube

fix #1708

The extension of the job result contains the wrong algorithm used to create the nonce.
The fix provide now the correct used algorithm even if the coin is forking to a new algorithm.

- forward the used algorithm from the miner

- remove all cryptonight coins (algorithm cryptonight can still be used)
- update README.md

- add ryo currency
- update documentation

- explicit loop unrolling

based on changes in @imperdin fork https://github.com/imperdin/xmr-stak/blob/master/xmrstak/backend/amd/amd_gpu/opencl/cryptonight.cl

- update pools.txt
- add new algorithm `cryptonight_haven`
- update all backends

- rename cryptonight_fast to cryptonight_masari
- set dev pool to cryptonight_monero

version prepere for the next release

The define of `_mm256_set_m128i` is not needed and avoid intel compiler throws a warning about it.

- avoid that a nonce which not fits to the current job is used (check jobId after start nonce is consumed)
- move jobId check into the if condition to get a new bunch of nonces
- CPU: add jobId validation after the start nonce is consumed

The login result of a pool contains the first job for the miner.
In the case where the pool is sending very fast after the pool login result
a new job it is possible that the newer job is processed faster than the job within the login result.
The result will be that the miner is mining an older job instead the newest (last received).

- enumerate all received messages
- trace the message id of the last procssed job
- skip all jobs where the message id is older than the last procesed id

If CUDA 9.X is used and the miner is compiled for `sm_70` and used with Volta GPUs than the miner
deadlocks if `threads` is not a multiple of `32`.

- use `__activemask()` to get all active lanes