Changes pagination defaults.

This changes the per_page_options to '100,500,1000'.
Improves default data

Adds two new types that can be used for the work packages formerly known
as planning elements.
Adds default colors.

Those are the colors that MS Project uses to sync.
Adds translations for new types.
Adds default colors to types.
More verbose error output.
Turns timelines into a new default module
Updates changelog.
Adds migration
Prefixes all tables w/ "legacy_"

Also removes planning_element_type_id on work_packages.
Merge branches 'feature/planning-element-type-migration' and 'feature/better-defaults' into feature/merge_planning_element_type_with_type