no need to store partition pointers for empty partitions

even when the pivot element is already in use
run astyle over Path.cpp
fix: we need to iterate until the last element before dead.

Since we iterate until i > end, do not do dead -1
ref: PLTSBlock::partition

to be more readable and less convoluted
ref: method add_partition_pointer() was called only once
ref: PartitionPointer::m_last is always the one added last
PartitionPointers::m_end only ever increased by 1

No need for a setter
Remove methods for white box testing from PLTSBlock