printf time left message to terminal tab
Move title bar logic out of hms().

In an effort to keep a functional core and imperative shell, I moved if
statements out of the hms() function and into the vsleep function which
unfortunately already had some conditional logic. I also eliminated an
extra variable and reduced some redundant code.
Change echo to printf for terminal tabs.
Optional configuration file.
Tests for config file.
Simplify test file boilerplate.
Improve portability in tests/run file.

Removed the use of the date command, which is very poor at portability.
Made the $MAIN path work for other users.