Project: help  b6bc8c1cfecc55bebff8dc64fddb63e3edc109b5

tdf#115255 and auto-expand contents per subitem

JavaScript stuff moved from online_transform.xsl to help.js.
Simplified bookmarks markup.
Span elements with class "input" and length more than 3 characters
can be copied to clipboard by mouse click.
Bubli's feature request for auto-expanding contents per subitem
is also implemented.
Logic for adding headings to index list was reimplemented.

Change-Id: I87b6f189a040a73a1ab9dda1ec9cd790b06da202
Reviewed-on: https://gerrit.libreoffice.org/49421Reviewed-by: Olivier Hallot <olivier.hallot@libreoffice.org>
Tested-by: Olivier Hallot <olivier.hallot@libreoffice.org>