Patch for static holidays with year

Attached is a rudimentary patch to lib/holidays.h and lib/holidays.c which allows you to optionally specify a year on static holiday entries. (Anything not in the current year is simply ignored.)

We needed this type of functionality for organization-chosen floating holidays. For example we get two days for Christmas, but which days vary. (This year 12/25, 12/26...next year 12/24, 12/25...then 12/23, 12/24...12/23, 12/26, etc.)

I'm certainly open to better solutions, but this appears to work-sample holidays for this year show up on info screens...samples for other years are ignored.

Cheers.

Darin Dugan

dddugan at iastate.edu