#349724 by sarvab: Fix that ensures '{panels_page}.access' is properly formed, such that it can be used properly in panels_page_access().

Contains both some code updates and a db update to ensure consistency.

Also updated some comments and docblocks.

Moved panels_page_access() and panels_page_get_title() into the read inc; also made temporary modifications to the former that (hackishly) cope with the pre-emptive access checking on all links.

Some refactoring, partially to accommodate changes suggested by douggreen. The basic context-loading problem has not yet been solved, however.

Save routines should now pretty much be functional. The problems appear to now pretty much be limited to context loading/generation at render time. It's not clear if the problem is with panels_page logic, the Panels engine, or some squirrely D6 changes.

Docblock updates and changes in code style for references to match merlin's ($a = &$b instead of $a =& $b)

Updated panels_page_load() to make use of a fetcher when called on an already-cached $panel_page that doesn't have the primary display loaded, although that use case is deprecated and should be avoided (for the sake of clarity). Other than that, mostly minor touch-ups.

Init import; all functions dealing with retrieval & rearrangement of panels_page-related data is contained here.

The panels_page_fetch*() family of functions were also notably refactored from when they last appeared in the panels_page.module file; they are now much more targeted, single-purpose entities with clear inputs and outputs. See the docblock additions for details.