Show reminder status message at the end

Also set up reminder timer in minutes, not seconds.
Disallow logging of clock-in reminder message
Fix wrong group prefix and name

Also remove mode lighter.
Move post-command handler above minor defun
Remove adding hooks to non existent functions
Fix wrong defgroup description
Allow C-g when toggling reminder to cancel changes.

Also, don't allow reminder to be toggled if user is currently IN and hook on to
timeclock's in/out hooks.
Fix clocked-in reminder not reactivating after being temporarily disabled
Update email address
Add LICENSE file
Move source files into src directory
Add readme file
Update project's readme file
Fix timeclock not using `timeclock-relative'

Replace some of timeclock's defuns with our own with the aim of fixing what is,
in my view, duplicate behaviour in the form of `timeclock-relative' and some
defuns accepting an optional parameter `today-only'.  This causes a particular
annoying problem when using some of timeclock's commands interactively where it
is not possible to pass t for `today-only' and the resulting output not being
what is desired.

The defuns remove the optional parameter `today-only' and use
`timeclock-relative' instead.
Update readme
Format comment section correctly