Added longToByte, intToByte, longFromBytes & intFromBytes; Associated c...

...hanges

Changed intToBytes's argument from (n: Long) to (n: Int)
long|intFromBytes has a new 8|4 byte arg method
Works, 
```
Pack.longToByte(0xFF00000000000000l, 0) == -1
Pack.longToByte(0x00FF000000000000l, 1) == -1
Pack.longToByte(0x0000FF0000000000l, 2) == -1
Pack.longToByte(0x000000FF00000000l, 3) == -1
Pack.longToByte(0x00000000FF000000l, 4) == -1
Pack.longToByte(0x0000000000FF0000l, 5) == -1
Pack.longToByte(0x000000000000FF00l, 6) == -1
Pack.longToByte(0x00000000000000FFl, 7) == -1

Pack.intToByte(0xFF000000, 0) == -1
Pack.intToByte(0x00FF0000, 1) == -1
Pack.intToByte(0x0000FF00, 2) == -1
Pack.intToByte(0x000000FF, 3) == -1 
```
all return true