Allows integrators to configure which fields should be used to produce
field "content" for indexed pages.
Before only "bodytext" was used. This is now configurable and "header"
was added to defaults.
Resolves: #134
Do not index content records of all pages while indexing pages in CMS
8.x.
We add same logic as for CMS 7.x, we extend the query to only fetch
records from current page.
Resolves: #135
Respect the following situations during indexing:
- Page is not reachable due to broken root line.
- Page is not reachable due to being below a recycler.