fix: some shard errors were not being raised and so the shard failed silently
when some kind of errors, like an Out of memory error occured.
fixed failing tests due changes in error message
implemented where clause splitter
Merge pull request #1198 from crate/m/where_splitter

implemented where clause splitter
move new relation classes into metadata package
renamed visitRelation
nested loop implementation
add a class to generate joinRelations from a list of analyzed relations

to rewrite select * from a, b -> select * from a cross join b
(and possible other join types in the future)
order by splitter
Merge pull request #1204 from crate/m/nestedloop

nested loop executor
Merge pull request #1207 from crate/h/orderby-splitter

orderby splitter
add relation attribute to SelectAnalysis

The AnalyzedQuerySpecification isn't fully integrated into
the Analyzer yet, but this commit should make it possible to
already adopt parts in the planner.
add relation symbol
remove integer, offset and having from AbstractDataAnalysis
remove schemaInfo from Analysis
use relation to resolve references
used sourceRelation instead of table attribute in planner
add a separate TableRelation instead of having TableInfo implement AnalyzedRelation
prepare executor for dynamic task creation and single PlanNode plans
remove additional inputTypes attribute from MergeNode