Improvement for compound meter count-in

Compound-meter-like time signatures (3*n/d where n > 1) are NOT counter as compound meters (one beat every 3 d units) but as 'triplets' of 'click'-'clack'-'clack' if:

1) the denominator is 1/4 or longer

2) the tempo for the compound unit would be slower then 60MM
Merge pull request #511 from mgavioli/count_in_fine_tuning

Improvement for compound meter count-in