Updated stopwatch with sclock system clock module.
Merge remote-tracking branch 'refs/remotes/humhu/sclock_refactor' into sclock_refactor
Re-introducing stopwatch.c/h during transition period.
Minor cleanup of both old/new modules.
Updating headers, back-porting usage documentation from stopwatch.
Making sclockReset() private.
Added documentation.
Merge branch 'refs/heads/master' into sclock_refactor
Switching from stopwatch to sclock module.
Updating sclock function call, switching to ms.
Fixing minor bug in function call.
Capturing a tick-based timestamp per row instead 
of a ms-based one.
Adding getter for MILLIS_FACTOR.
Adding i2c_driver.c/.h . Following committs to reflect updates to affected modules.
Updating XL module to use i2c_driver.
Gyro module updated to use i2c_driver
Adding filter-avg.c/.h , standalong average filter modules.
Changed name of filter-avg to dfilter_avg
Removed T5IE references.
removed extraneous Nop()