Remove backtrace length and make all chunks with only one return (backtrace) address.

To make mem-leak-checker less power cunsuming, backtrace was reduced to one address.
Second reason for this restructuralization of data chunks is that previous solution was quite hard to achieve on all platforms (arm's glibc backtrace is not working correctly and libunwind is really heavily leaking memory).
Change data format according to documentation. Backtrace size is hard coded to store only first return value.
Backtrace is hard coded to prevent any mismatch in future changes. No need for configurable backtrace size any more, better way how to make c++ new and delete return addresses exist.

Also data structures for storing data chunks are restructuralized. Basic data structure is union which si containing the rest os another data structures.