Merge branch 'cal-fourth' of git://github.com/kerolasa/lelux-utiliteetit

* 'cal-fourth' of git://github.com/kerolasa/lelux-utiliteetit:
  docs: cal: stop telling year 9999 is upper limit
  tests: check cal works when year is far in future
  cal: remove arbitrary limit of maxium year being 9999
  cal: use Claus Tøndering's day of the week algorithm
  cal: simplify day_in_week() calculation
  cal: mark all functions static
  cal: stop trimming whitespaces
  tests: add cal day color corner cases
  docs: cal: add --color option description to manual page
  cal: add --color to usage()
  cal: support --color[={auto,always,never}]
  cal: de-duplicate julian specific functions
  cal: remove unnecessary initializations
  cal: simplify calendar reformat calculations
  tests: add calendar reformation check
  cal: clean up use of constants
  cal: convert function like definitions to functions
  cal: fix preprocessor directive indendation