Merge branch 'release/5.2'
Bumps version numbers for development version. Refs #12.
Adds code to calculate optimal axis steps. Refs #13.
Removes camelCase style. Refs #13.
Fixes naming and usage of default_max_ticks. Refs #13.
Exports scale calculations to C. Refs #13.
Exports Nice_scale getters to C. Refs #13.

Works around https://github.com/Araq/Nimrod/issues/1189.
Documents task in changes log. Refs #13.
Merge branch 'feature/t13_graph_scale'
Relaxes assert and allows nil params in API. Refs #13.
Tweaks calculate proc to allow zero range inputs. Refs #13.
Adds functions to store analytics settings. Refs #17.
Documents task in changes log. Refs #17.
Merge branch 'feature/t17_objc_tracking_settings'
Improves title of release steps to identify document.
Updates version numbers for v6 release. Refs #18.
Merge branch 'release/6' into stable