[MONDRIAN-2124]  Cell queries are not aggregated when ignored/un-matched columns are present

There's logic in AggregationManager.findAgg() which determines whether or not it's possible to omit the rollup when pulling data
from an aggregate table.  This is allowed, for example, if the granularity of the request matches the granularity of the agg table.
Formerly we were determining whether the granularity is the same  by looking at whether the bitkeys matched, and whether
the agg table was fully collapsed.  This left open the possibility that ignored or unused columns in the agg table could result in difft
 granularity.  Now we take the conservative stance that presence of any ignored column means that we have to rollup.
 Similary, for distinct-count measures, if an ignored or unused column is present, we now make the assumption that the agg table
 cannot be safely used.
Merge pull request #333 from mkambol/mondrian-2124

[MONDRIAN-2124]  Cell queries are not aggregated when ignored/un-matched...