Slowed down safeGuard task

Slowed down safeGuard task by adding a wait1Msec() call to every
loop. This allowes the NXT to spend more time dealing with your
engine, while still checking the encoder limits fast enough to stop
any out-of-bounds movement before the robot breaks.

To tweak the delay, just change the GUARD_UPDATE_TIME global to the
desired number of milliseconds.
Merge pull request #4 from mfabel/delay

Slowed down safeGuard task