srl_buffer: make SRL_SET_BODY_POS accept buf instead of enc
Sereal::Merger: fill header in output buffer
Sereal::Merger: improve parser tracing
Sereal::Merger: fix nasty bug
Sereal::Merger: add support of REFP
Sereal::Merger: dont dedupe short (<3 chars) strings
Sereal::Merger: fix compilation warnings
Sereal::Merger: implement parser stack as simple array
Sereal::Merger: use srl_stack_t to keep track of tracked_offsets