Change structs and refactor a few. STATUS: compile OK.

Not tested.
Wrote new replay algorithm but not tested yet
Rename global_id -> id
Impl read_segment
Remove read_segment_header_device and unified with read_whole_segment
Refactor
Fix a bug. Change ">>" to "<<"
FIX le32_to_cpu -> le64_to_cpu because id is 64 bit-wide
Merge branch 'feature/log-replay-redesigned' into develop