Merge branch 'lt/approxidate'

* lt/approxidate:
fix approxidate parsing of relative months and years
tests: add date printing and parsing tests
refactor test-date interface
Add date formatting and parsing functions relative to a given time
Further 'approxidate' improvements
Improve on 'approxidate'

Conflicts:
date.c

diff --cc cache.h
Simple merge