- expose cryptonight_lite_v7, cryptonight_heavy and cryptonight_v7
- remove cryptonight_lite

Graft is forking soon, with updated software released yesterday, to what
will be v8 in Graft (current Graft cryptonight algorithm is graft v7).
This commit updates the `graft` algorithm to recognize the fork and
switch algorithms.

Fork annoucement:
https://www.graft.network/2018/04/12/patch-1-1-1-released-major-network-update-block-65110/

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`

sumokoin is broken if `bfactor >= 5` is used (default for windows)
sumokoin for `sm_20` is broken due to the missing extern shared memory

- call phase3 kernel two times if sumokoin is enabled
- create extern shared memory for phase3 kernel

fix #1297

If sm_20 is mixed with other architectures the detection for the minimal supported architecture is broken.

- 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 :-(

- documentation: change `aeon` to `aeon7`
- change `case` order in `switch` statements
- update README.txt

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

- remove call `IsCurrencyMonero` with `cn_select_memory`

fix #1202

revert #1198, the block size is limited to 84byte

move option `--currency` down

The OpenCl code is only supporting jobs up to 84byte

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

- add project picosha2
- add license notes for picosha2