Intersect queries added

4 tests for INTERSECT queries have been added with their expected
results
Except queries added

four Except queries and expected results added
SetOpName added

set operations now output their name in the output
Union Query added

Union queries and expected files added
Order by set test

Order by operator tested set-order.sql
SetOperatorNode change and Offset/Limit test added

Query and expected output now added and the SetOperatorNode class now
has the ability to print these values
Multiset operation test added

Added query that combined union, intersect and except as well as its
expected file
clean up SetOperatorNode

general cleaning
changed filename

Intersect-2.sql changed to intersect-2.sql
updated intersect filename
merge JerettS: Intersect, Except and Union operators

Merge pull request #114 from JerettS/sql-parser/Intersect-Except-
https://github.com/FoundationDB/sql-parser/pull/114