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)
whirlpool: remove dead code, win 2ms in final hash