output: add the --color parameter (-C)

disabled by default or if syslog option is set

Signed-off-by: Tanguy Pruvot <tanguy.pruvot@gmail.com>
groestl: small optimisation (nist5 + 100kH on a 750Ti)

But, almost nothing on X15, no big changes...
whirl: add missing merkle for some pools
Makefile: luffa was using more than 80 regs (10 vs 14ms)

add easy switch for nvcc target arch

and move duplicated sha2 to sph folder
scrypt: fix implicit function declaration
add x17 algo, cleaned djm34 commit

todo: visual studio...
x17: update vstudio project
heavy: warnings and tabs (no changes)