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.

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.

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

fix: use `.sX` to access vector components

- 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

- 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

- 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

fix #1505

- fix possible deadlock of the executor thread
- fix racecondition during the job consumation
- remove switch_work in all classes `minethd`
- move `consume_work` into `globalStates`

solve #1494

- add algorithm `cryptonight_v7_stellite` (internal named: `cryptonight_stellite`)

- add algorithm `cryptonight_lite_v7_xor`
- update documentation

- fix that to much OpenCL calls whre used if cache is disabled

remove fork version for sumokoin and monero7

- allow the dev pool to fork on a different block version than the user descriped coin

All algorithm are centered around the user coin description.
It is allowed to have two two different coin algorithms in the user coin description.
It is only allowed to use algorithms for the dev pool coin description those are used in the user coin description.
There are two ways to define a non forking coin.
  - set both user coin algorithm descriptions to the same algorithm and set version to zero
  - set the first algorithm in the user coin description to something you like to use in the dev pool
    and set the second algorithm to the correct representation of the coin. Set the version to 255.
    This will allow that the dev pool can mine on a different coin algorithm than the not forking user coin.
    Do not use an algorithm with different scratchpad size for the dev pool.

In the case where the dev pool mines on a higher version than a monero fork coin the miner is not resetting the algorithm.
This PR select the correct algorithm each time the block version hash changed.

- add CLI flag to explicitly use non AMD OpenCL and devices
- adjust OpenCL output (use OpenCL instead of AMD if --altOpenCL is sued)
- optimize NVIDIA OpenCL auto suggestion

Use the maximum scratchpad size from before and after the fork.

- remove version numbers within the kernel
- create seperate program context for each mining algorithm
- remove kernel `cn1_monero` is now integrated in `cn1`
- remname `cnX` kernel in `cnX + algorithmNumber`

- fix that version argument was not passed to extended kernel parameters

-rename `mining_fork_height` to `*_version`

- add `fork_height` to currency
- refactor algorithm selection

fix #1218

- remove inline function with ugly macro :-(

allow to disable the OpenCl cache
  - usefull for read only systems
  - usefull for unknown errors during cache reading

fix warning

```
/Users/user/xmr-stak/xmrstak/backend/amd/amd_gpu/gpu.cpp:481:11: warning: using the result of an assignment as a condition without parentheses [-Wparentheses]
                if( ret = clGetProgramInfo(ctx->Program, CL_PROGRAM_BINARIES, num_devices * sizeof(char*), all_programs.data(),NULL) != CL_SUCCESS)
```

- add new pow for AEON
- fix missing cryptonight-heavy selection for multi hashes

change warning when precompiled OpenCL code is not found

Co-authored-by: psychocrypt <psychocryptHPC@gmail.com>
Co-authored-by: fireice-uk <fireice-uk@users.noreply.github.com>
Co-authored-by: Lee Clagett <code@leeclagett.com>
Co-authored-by: curie-kief <curie-kief@users.noreply.github.com>

A redefinition of a variable in a local scope avoid that the intensity is rounded to a multiple of the work size.

Reduce OpenCL start time by using a self made compiler cache.

- store compiled OpenCL binary
- load OpenCl binary if available

fix double definition of define `MEM_CHUNK`

guard error types those are only defined in OpenCL >1.1

- add new option `comp_mode` to the amd config
- disable `if guards` within opencl kernel if `comp_mode : false`

allow usage of Mesa OpenCl