Converted log calls across src/, examples/, and test/ to use DEBUGF/TRACEF/ERRORF/etc. macros instead of std::string + operator+. This eliminates temporary heap allocations on every log call, which matters on memory-constrained MCUs.
Fix for link validation failure when poackets contain new MTU in payload
from RNS 1.0 (courtesy of @jlpoolen).
Optimization of announce re-broadcasts from RNS 1.0.
