#27: parsing: assume local time zone by default
#27: add and fix tests
#27: refactor time zone assumption API
#27: fix get_time_zone dumper for 'Z'
Merge branch 'master' into set_local_timezones_default
#27: implement feedback and tidy up
Merge pull request #43 from benfitzpatrick/set_local_timezones_default

Set the local time zone as the default
#34: better dumping of negative intervals
address feedback
#34: support parsing as well
Merge pull request #44 from benfitzpatrick/34.negative-intervals

#34: better dumping of negative intervals
Add ISO 8601 primer to the README file
Merge pull request #46 from benfitzpatrick/doc-readme

Add ISO 8601 primer to the README file
Merge branch 'master' into speed_up_tests
try Calendar class
isodatetime: speed up tests