Add stubs and error checks

Bit api checks for numbers larger than 32bits (A bug in the Lua VM
breaks this)
Fs api checks for imvalid paths
Rewrote fs.getDir
filesystem.format converts all backslashes
Reworte sanitiser with stack based implementation.
Fixed filesystem.pathContains
Added stub to os.setAlarm
Added stubs to peripheral api
Added stubs to redstone api
Corrected typo in redstone api
Removed math.mod and string.gfind from Lua