do busy wait in central scheduler if queue is empty
fixes an issue due to copying the main to the delta dictionary during merge and not building the tree index for the orderindifferent dictionary
Better naming of methods in dictionary for lower and upper bound searches
Changes groupkey index to use posting and offset vector instead of maps
Adds tests for groupkey index
Removes locks for TPC-C stored procedures
Adds define for NUM_RESERVED_CORES in shared scheduler for number of cores reserved for hyrise internals like event loop or logger threads
Fixes a bug in IndexAwareTableScan