Distinguish Union and UnionAll

This moves the expected behavior from UnionScan to UnionAll.
Union will remove duplicate positions while UnionAll will not.
Remove code comments from PlanOperation
cleaned up access/NestedLoopEquiJoin
Merge pull request #86 from timbokopter/feature/cleanup_NestedLoopEquiJoin

cleaned up access/NestedLoopEquiJoin
Add binutils-dev to hyrise recipe.

Fixes #89
Merge branch 'master' of github.com:hyrise/hyrise
Merge pull request #81 from bastih/feature/Distinguish_Union_and_UnionAll

Distinguish Union and UnionAll
remove check for duplicate inputs; issue #88
Merge branch 'master' of git://github.com/hyrise/hyrise into mutex_list
Merge remote-tracking branch 'upstream/master'
Update .gitignore for build/dummy
Fix incorrect handling of TableRangeViews in SimpleTableScan parallelization
Merge pull request #93 from bastih/fixes/range_view_split_combine_fix

Fix incorrect handling of TableRangeViews in SimpleTableScan parallelization
Merge branch 'master' of git://github.com/hyrise/hyrise
Merge branch 'mutex_list'