includelet-procs.tcl

- toc includelet:
* new flag: "-renderer" (default "")
specify an explicit renderer. This is an alternative to the
classic "rendering by style", where there style determines the renderer.
* new flag: "-include_in_foldertree" (default true)
it is now possible to avoid inclusion of all folder-tree element
in the standard folder tree. Default set for backwards
compatibility.

- new tree renderer "bootstrap3horizontal" for rendering
a tree as a horizontal bootstap based menu with dropdown.
This can be used e.g. for rendering the table of contents
for a folder based on the page_order

{{toc -renderer bootstrap3horizontal -include_in_foldertree 0 -folder_mode 1}}

where the elements of the toplevel hierarchy (e.g. 1, 2) are displayed as
menubuttons, having the elements of the lower hierarchy as menu
entries (e.g. 1.1, 1.2, 2.1, 2.2, ...)