Initial support for creating new year directory on the 1st of the year.
Added helper methods to 43f-test.sh to allow temporarily changing & restoring date/time in unit tests.
Fixes to support for creating new year directory on the 1st of the year.
Implemented test for creation of new year directory on January 1st.
Update README.md & CONTRIBUTING.md to note disabling of functional tests that change system date & time.