Fixes redirection of planning elements.

Creating a new planning element sends a "see other" with the new URL of
the planning element. When created via the API, the redirection URL will
be the API URL.
Fixes timelines.js url handling.

Version 2 of the API changed some URLs. This commit removes the
global_prefix in favor of the api_prefix and fixes the URL generation to
use the new end-points.
Fixes URL generation in modal.js

Timelines URL changes made these neccessary, as use of "/" at the end of
prefixes is now discouraged.
Disables API on timelines controller.
Disables API on scenarios controller.
Disables API on reportings controller.
Disables API on planning elements controller.
Disables API on planning element types controller.
Disables API on project types controller.
Disables API on authentication controller.
Disables API on planning element journals controller.
Disables API on planning element statuses controller.
Disables API on planning element type colors controller.
Disables API on project associations controller.
Disables API on reported project status controller.