implemented where clause splitter
Merge pull request #1198 from crate/m/where_splitter

implemented where clause splitter
move new relation classes into metadata package
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)
renamed visitRelation
nested loop implementation
Merge pull request #1204 from crate/m/nestedloop

nested loop executor
order by splitter
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