make room for VERSION
add year to tagline, with prev/next year links

* added year to tagline
* added feedline at the bottom
* moved feed from tagline to feedline
* added last_year & next_year labels/links
* added #feedline css id to mimic #tagline
added year-links command line switch
offer advcal -y, as documented
update Pod usage in bin/advcal

to match WWW::AdventCalendar
Merge branch 'topic/yearlinks'
v1.111

        - add --year-links to add links to prev/next years' calendars
          (thanks, Len Jaffe!)