Returns the host count for a table and a state
get_other_count(table_hosts, name_cur, active_hosts, name_count, cur)
a table.hosts
name of the cell, one of "current.in" or "current.cell.raster"
a boolean vector of active hosts
name of the count, one of "host.count.A" or "host.count.B"
a data.table with the state
data.table containing state.ID (col1) and count (col2)