Recommendation is to avoid using the year nomenclature as this
information is already encoded in the git repo. Avoids needing to
repeatly update.
Also updates AUTHORS.txt from current repo with contributor names
The sheet list is returned as a copy of the cached list rather than a
reference to prevent external code from changing the list. While not as
performant, it eliminates the risk of the sheet list being altered in
ways that could break the schematic. The sheet list should only be
updated by calling SCHEMATIC::RefreshHierarchy() when any appropriate
sheet changes are made.
Note to developers: there is something inherently different about how the
QA tests are loading and handling schematics versus the schematic editor.
Using the cached sheet list for the SCHEMATIC object will cause some QA
test to fail. This is why SCHEMATIC::Hierarchy() has not replaced
SCHEMATIC::BuildSheetListSortedByPageNumbers() everywhere.
Also removes the side-effect that SCH_SHEET_LIST's
c'tor would sort the list (and write virtual page
numbers) anytime the starting sheet was the root.
Also, definitely don't build a SHEET_LIST (sorted or
otherwise) if you're not even going to use it.
Also don't build SCH_SHEET_LISTs on idle events. Better
to just always have the Next Sheet button enabled (we
already beep if you click it and there's no next sheet).
Also, use a SCREEN_LIST when you can. It's much cheaper
to create.
