Building tree of the directory.
Write go run main.go <directory> <-f> to run the program. Replace with path to the directory whose tree you want to see (. in case of current directory). Use -f
if you want to get tree with files. Otherwise only directories will be printed.
Functions pipeline and implementing some functions to count hash with combination of crc32 and md5.
Optimitzed code using pprof. Compare common.go and fast.go.