Thanks to @bep's new, brilliant helpers.Deprecated() function,
the following functions or variables are transitioned to their
new names, preserving backward compatibility for v0.14
and warning the user of upcoming obsolescence in v0.15:
* .Url → .URL (for node, menu and paginator)
* .Site.BaseUrl → .Site.BaseURL
* .Site.Indexes → .Site.Taxonomies
* .Site.Recent → .Site.Pages
* getJson → getJSON
* getCsv → getCSV
* safeHtml → safeHTML
* safeCss → safeCSS
* safeUrl → safeURL
Also fix related initialisms in strings and comments.
Continued effort in fixing #959.
Prior to this commit, `HasMenuCurrent` and `IsMenuCurrent` on `Node` always returned false.
This made it hard (if possible at all) to mark the currently selected menu item/group for non-Page content (home page, category pages etc.), i.e. for menus defined in the site configuration.
This commit provides an implementation of these two methods.
Notable design choices:
* These menu items have a loose coupling to the the resources they navigate to; the `Url` is the best common identificator. To facilitate a consistent matching, and to get it in line with the menu items connected to `Page`, relative Urls (Urls starting with '/') for menu items in the site configuration are converted to permaLinks using the same rules used for others’.
* `IsMenuCurrent` only looks at the children of the current node; this is in line with the implementation on `Page`.
* Due to this loose coupling, `IsMenuCurrent` have to search downards in the tree to make sure that the node is inside the current menu. This could have been made simpler if it could answer `yes` to any match of any menu item matching the current resource.
This commit also adds a set of unit tests for the menu system.
Fixes#367
