clear src
clear pins.md & op_codes.md
update readme.md
change ignore
before change shl & shr B to A
after change shl & shr B to A
add r3 to reg_content
add r4
add succeed demo
add testfile
update readme
update op_codes & pins but with error in pins
done
Merge pull request #4 from whuream/ream's

Ream's
deleted files
delete demo
move and delete files
update readme
add *.vhd files
merge from Dev-Ream