log handler
work
read works
improve code
add some draft test
fix variable names
log.py: rename to load_last_block
log.py: determine seq/buf/block_first_seq by subfunc
log.py add log
log.py: rename to block_seq
log.py rename to block_first_seq
introduce fucn in_one_block() and align()
log test_log.py passed
log.py fix 0 bytes file issue
log.py read() returns next_seq