fix a typo for displaying message
	modified:   ../../HybridAutomata/ha_reach.m
record running time for performance analysis
	modified:   ../../HybridAutomata/ha_create.m
	modified:   ../../HybridAutomata/ha_reach.m
Add code for CAV14 paper
	modified:   run_dpll.m
fix a typo
Merge /ubc/cs/home/c/chaoyan/cra
submit for CAV14 paper