bug #890404 by Agileware, marvil07: Avoid array_merge_recursive() on hook_votingapi_results_alter() function.
New aggregation functions for votingapi cache table were assuming there
will be only one tag, that's now fixed.
In the other side, we are now avoiding use array_merge_recursive() and
instead, add the values directly to the $cache array
fix aggregation functions for positives/negatives so they calculate all tags results instead of only one tag result