A graphical countdown timer like the timer used in sprints popularized by google ventures
Usage:
python countdowntimer.py [-h <#>] [--hours=<#>] [-m <#>] [--minutes <#>] [-s <#>] [--seconds <#>] [-x ] [-y ] [-q or --quiet]
If the -q or --quiet flag is set then don't print anything on the command line, otherwise print a countdown also.
Requirements: Python3, tkinter (see earlier commit tag=v2.0 for python2 version)
To install requirements: apt install python3-tk