Add (failing) sqlite delete test
Implement sqlite delete
Implement sqlite writeLiteral
Refactor creating & filling tbl1
Add (failing) sqlite update test
Implement sqlite update
Drop Sql prefix in favor of sql namespace
Right indent
Drop universe
Drop 'Rel' prefix in favor of 'relational' namespace
Rename RelationalAlgebra.scala -> relational.scala to match object name
Right-indent
Have QueryName as type alias
Have Order in own file / package
Add equals to Schema; also apply, unapply, hashCode

Not using case classes to avoid forcing lazy schemaMap
Label -> Attribute
schemaMap -> environment
Introduce Environment
Add TODO
Refine Query{Project,Restrict} field types