Factor/To do/Misc

• initialize the entire mersenne twister state with random numbers, not just the intial state with a single 32bit number
• sgn needs a branchless implementation for integers and a correct one for floats

Fixed:

• we can get rid of the optimized slot on words
• Windows doesn't like files with names starting with ., so just look for factor-rc and factor-boot-rc there
• implement a shuffle word (fixed: added "randomize" to extras/sequences/lib)