Fixed AUTO2.SAV bug introduced in [ea7e7451230de Sys: Add detection for a game config directory].

This patch fixes AUTO2.SAV never being created/used for autosaves.
The Sys::auto_save function was still using relative paths for save games, rather than the
dir_config directory.
OGFILE: Removed legacy Windows-only code that checks available Disk Space.

The code was already half-broken, because it didn't use absolute paths
to check for the savegames. It is also best to let the OS decide whether
or not there is enough room.
Savegame list now sorts AUTO.SAV and AUTO2.SAV to the top of the list.
Fixed disappearing news messages bugs, when displaying only Major news.
OSYS: auto_save: Fixed debug_session autosave code, and renamed savegame to "DEBUG#.SAV"
Fixed crash when rewarding a neutral unit (in neutral spectator mode).

This patch also unhides the Reward button for your disguised spies.
Fixed crash when trying to capture firm in neutral spectator mode.

The capture firm button no longer displays when the capturing party is
the neutral nation. This fixes the possibilty of crashing the game when spectating.
Fixed bug with hidden, but clickable, buttons with weapons. Weapons now have 'return to camp' button.
Rewarding a group of units will no longer 'reward' weapons
Added macro DYNARRAY_DEBUG_ELEMENT_ACCESS to toggle debug versions of operator[] for DynArray-derived collections

Defining DEBUG changes all operator[] implementations to a version that checks for non-null.
This patch allows separate toggling of this behaviour, without having the full DEBUG code.
Note that defining DYNARRAY_DEBUG_ELEMENT_ACCESS is a severe performance hit.
Merge branch 'MicroVirus-crash-fixes-aug-2014'