add tar.gz compression
remove unnecessary copy of directory and implement byte completed progress count
improve compression progress counter
add extract .tar.gz
add extraction progress counter, improve progress counters
add split and concatenate with progress
improve concatenate progress to use byte count instead of file count
fix handling of broken symlinks in get_size() and compress()
ignore hidden files in indir in cat_files()
add MD5 hashing for unique ID generation
improve unique ID generation to use SHA256 and append time()
add encrypt and decrypt functions
update split_file() and cat_file() to remove source files once done
add progress monitor for encrypt() and decrypt()
experiment with creating a GUI using Flask
add Bootstrap progress bar updated by python backend via sijax
add realtime update of progress bar from python backend
add form for file path with communication to backend via sijax
add overlayed progress bars for upload steps 1-4
add field to enter passphrase