tidy and make code more consistent with other programs
getFilterData() now returns a pointer which we increment in the calling code
this means we only need to only call getFilterData() once for a read/region
Dropped dump and min_region_count options, min_region_count now calculated dynamically.
Use multiple regions to set the region state if the cluster density is too low.
Summary region tables required for tileviz plots generated dynamically.
Added code to detect bad tiles, currently not used