Implemented alignment by major unit in the time scale. This allows showing the first tick of a larger unit like days in a special way and is part of the basis of the time series scale.
* Make parseTime private
* start on fixing time scale
* Reimplement existing functionality
* Tidy tests
* Fix labels for non-linearly sized units
Months, quarters and years have non-constant numbers of seconds. A scale that's linear WRT milliseconds produces incorrect tick labels due to the label formatting losing precision (eg year labels lose month and day so a label of 2016-12-32 displays as 2016 instead of 2017).
* Re-implement tick generation
As in v2.5
`karma.conf.ci.js` has been merged into `karma.conf.js` for local testing consistency: `gulp unittestWatch` has been replaced by `gulp unittest --watch` and thus use exactly the same config file. Upgrade to latest jasmine and karma packages and remove deprecated `gulp-karma` dependency (directly use `karma.Server` in gulp).
Split `test/mockContext.js` into smaller `test/jasmine.*` modules to make easier unit tests maintenance and finally, move all `*.test.js` files under the `test/specs` folder.
