Routine for time-interval change permutation

	new file:   mcode/perm_test_tIntChgs.m
Subroutine for drawing significance legend

in the time-interval change results plot
	new file:   mcode/show_legend_sig.m
Subroutine of perm_test_fmtChgs.m

for getting continuous stretches of significant changes under the p-value
threshold P_THRESH_UNC

	new file:   mcode/get_sig_stretches.m
Subroutine for timing response ratio analysis

	new file:   mcode/analyze_timing_response_ratio.m
Added option --show-fmts

	modified:   mcode/view_rhy_behav_trial.m