updates for the monero-v1 pow tweaks

[vtnerd]

These are updates for the monero - version 1 PoW changes. For this version, I modified the long state directly instead of manipulating some of the state variables. The entire context is heap allocated, so I wasn't sure what the compiler was going to do with aliasing already. Some other versions I modified the state directly, especially if they were stack variables.

[vtnerd]

Also note that this is going directly into the master branch, and not the dev branch.

[lhirlimann]

Any chances of this getting merged?

[2010phenix]

@vtnerd with this update we can mine Graft?

[philtimmes]

Bus error on run on ARMv7a CPU.

[philtimmes]

Also, bad hashes on x86_64

[DarrenRainey]

yeah just checked it on armv7l and got a seg fault looks like the code is uses some armv8 specific features heres a gdb log

(gdb) run
Starting program: /usr/src/cpuminer-multi-monerov7/minerd -a cryptonight-monero -o stratum+tcp://xmr.pool.minergate.com:45700 -u darren@darrenraineys.co.uk -p x -t 1
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/arm-linux-gnueabihf/libthread_db.so.1".

Program received signal SIGILL, Illegal instruction.
0x000c00be in _armv8_pmull_probe ()