Removed duplicate code
Merge pull request #91 from andig/tests

Merging as only test cases affected.
Remove calculating min/max/avg for groups. Not needed, bad for performance, bad idea.
Allow multiple uuids
Merge pull request #93 from andig/vzclient

Allow multiple uuids
fixed a typo
Improved aggregation optimizer- less queries, fixed MySQLOptimizer tuples=n optimization not being called
Ensure clean properties aren't considered dirty
Merge pull request #94 from andig/agg-fix

Improved aggregation optimizer
Merge pull request #95 from andig/fix-entity-persist

Ensure clean properties aren't considered dirty
Merge pull request #92 from andig/aggregate-view

Remove calculating min/max/avg for groups. Not needed, bad for performan...