added parallel hash build
removed one recurring vector.size call
further performance tuning by avoiding calls to vector.size()
Adding Single Key Hash Building

Adding HashJoin with Single Keys for Values
fixed an error in hash_table_test
Merge remote-tracking branch 'upstream/master' into feature/parallel_HashBuild
added some comments
added hash_build tests
merged singlevaluejoin and parallel hash build
removed google profiler.h from header
added parallel hash build

removed one recurring vector.size call

further performance tuning by avoiding calls to vector.size()

fixed an error in hash_table_test

added some comments

added hash_build tests

Adding Single Key Hash Building

Adding HashJoin with Single Keys for Values

removed google profiler.h from header

Automatically Selecting the Appropriate HashMap Type

Updating the MergeHashTable with appropriate hash table choice

Bugfix in Interface
Merge branch 'feature/single_value_join' of github.com:hyrise/hyrise into feature/single_value_join

Conflicts:
	src/bin/units_access/hash_build.cpp
	src/lib/access/HashBuild.cpp
	src/lib/access/MergeHashTables.cpp
	src/lib/storage/HashTable.h
Merge pull request #12 from hyrise/feature/single_value_join

Feature/single value join
Merge branch 'master' of git://github.com/hyrise/hyrise
Add expression registration facility

* Add registration facility for custom AbstractExpressions
* Rework SpecialExpression to ExampleExpression
* Add example documentation
Merge pull request #13 from bastih/feature/tablescan_improvements

Add ability to create custom expressions

* Add registration facility for custom AbstractExpressions
* Rework SpecialExpression to ExampleExpression
* Add example documentation
Merge branch 'master' of git://github.com/hyrise/hyrise