Started MSP430 Launchpad sample.

Copied files from Trinket sample into new Launchpad sample. Populated
Makefile and system header, but additional configuration for system
clocks is needed. Main source is empty. Compiles successfully.
Removed hex file target from Launchpad sample Makefile, as it is not needed for programming.
Copied main sources from Trinket sample to Launchpad sample.
Detections for overflow and unitialized cycle time

Added detection for uninitialized (zero) compare-match and
compare-matches-per-cycle values in StarTimer function. Added check for
cycle time overflow in SetTimerCycleTimeSec caused by multiply
operation.