Add: store headers for most savegame chunks

When a header is added, the chunk changes from CH_ARRAY type to
CH_TABLE type.

src/table/settings/gameopt_settings.ini

@@ -158,15 +158,6 @@ min      = MIN_SNOWLINE_HEIGHT * TILE_HEIGHT
 max      = UINT8_MAX
 to       = SLV_22
 
-[SDT_NULL]
-length   = 1
-from     = SLV_22
-to       = SLV_165
-
-[SDT_NULL]
-length   = 1
-to       = SLV_23
-
 [SDTC_OMANY]
 var      = gui.autosave
 type     = SLE_UINT8

src/table/settings/settings.ini

@@ -62,7 +62,6 @@ SDT_BOOL   =   SDT_BOOL(GameSettings, $var,        $flags, $def,
 SDT_OMANY  =  SDT_OMANY(GameSettings, $var, $type, $flags, $def,             $max, $full,     $str, $strhelp, $strval, $pre_cb, $post_cb, $from, $to, $load, $cat, $extra, $startup),
 SDT_SSTR   =   SDT_SSTR(GameSettings, $var, $type, $flags, $def,                                                       $pre_cb, $post_cb, $from, $to,        $cat, $extra, $startup),
 SDT_VAR    =    SDT_VAR(GameSettings, $var, $type, $flags, $def,       $min, $max, $interval, $str, $strhelp, $strval, $pre_cb, $post_cb, $from, $to,        $cat, $extra, $startup),
-SDT_NULL   =   SDT_NULL(                                                                $length,                                                     $from, $to),
 
 [validation]
 SDTG_VAR = static_assert($max <= MAX_$type, "Maximum value for $var exceeds storage size");
@@ -355,12 +354,6 @@ strhelp  = STR_CONFIG_SETTING_LANDSCAPE_HELPTEXT
 strval   = STR_CHEAT_SWITCH_CLIMATE_TEMPERATE_LANDSCAPE
 cat      = SC_BASIC
 
-; Snow line (or snow_line_height * TILE_HEIGHT)
-[SDT_NULL]
-length   = 1
-from     = SLV_97
-to       = SLV_164
-
 [SDT_OMANY]
 var      = vehicle.road_side
 type     = SLE_UINT8
@@ -536,11 +529,6 @@ str      = STR_CONFIG_SETTING_MAX_TUNNEL_LENGTH
 strhelp  = STR_CONFIG_SETTING_MAX_TUNNEL_LENGTH_HELPTEXT
 strval   = STR_CONFIG_SETTING_TILE_LENGTH
 
-# construction.longbridges
-[SDT_NULL]
-length   = 1
-to       = SLV_159
-
 [SDT_VAR]
 var      = construction.train_signal_side
 type     = SLE_UINT8
@@ -843,11 +831,6 @@ strhelp  = STR_CONFIG_SETTING_TRAIN_LENGTH_HELPTEXT
 strval   = STR_CONFIG_SETTING_TILE_LENGTH
 cat      = SC_BASIC
 
-; vehicle.mammoth_trains
-[SDT_NULL]
-length   = 1
-to       = SLV_159
-
 [SDT_VAR]
 var      = vehicle.smoke_amount
 type     = SLE_UINT8
@@ -860,11 +843,6 @@ str      = STR_CONFIG_SETTING_SMOKE_AMOUNT
 strhelp  = STR_CONFIG_SETTING_SMOKE_AMOUNT_HELPTEXT
 strval   = STR_CONFIG_SETTING_NONE
 
-; order.gotodepot
-[SDT_NULL]
-length   = 1
-to       = SLV_159
-
 ; path finder
 
 [SDT_BOOL]
@@ -1083,12 +1061,6 @@ strhelp  = STR_CONFIG_SETTING_FREIGHT_TRAINS_HELPTEXT
 strval   = STR_JUST_COMMA
 post_cb  = UpdateConsists
 
-; order.timetabling
-[SDT_NULL]
-length   = 1
-from     = SLV_67
-to       = SLV_159
-
 [SDT_VAR]
 var      = vehicle.plane_speed
 type     = SLE_UINT8
@@ -1123,11 +1095,6 @@ strhelp  = STR_CONFIG_SETTING_PLANE_CRASHES_HELPTEXT
 strval   = STR_CONFIG_SETTING_PLANE_CRASHES_NONE
 cat      = SC_BASIC
 
-; station.join_stations
-[SDT_NULL]
-length   = 1
-to       = SLV_159
-
 [SDTC_BOOL]
 var      = gui.sg_full_load_any
 from     = SLV_22
@@ -1151,11 +1118,6 @@ from     = SLV_22
 to       = SLV_93
 def      = false
 
-; station.nonuniform_stations
-[SDT_NULL]
-length   = 1
-to       = SLV_159
-
 [SDT_VAR]
 var      = station.station_spread
 type     = SLE_UINT8
@@ -1277,10 +1239,6 @@ def      = false
 str      = STR_CONFIG_SETTING_MULTIPINDTOWN
 strhelp  = STR_CONFIG_SETTING_MULTIPINDTOWN_HELPTEXT
 
-[SDT_NULL]
-length   = 1
-to       = SLV_141
-
 [SDT_BOOL]
 var      = economy.bribe
 def      = true
@@ -1365,10 +1323,6 @@ strhelp  = STR_CONFIG_SETTING_DESERT_COVERAGE_HELPTEXT
 strval   = STR_CONFIG_SETTING_DESERT_COVERAGE_VALUE
 cat      = SC_BASIC
 
-[SDT_NULL]
-length   = 4
-to       = SLV_144
-
 [SDT_VAR]
 var      = game_creation.starting_year
 type     = SLE_INT32
@@ -1380,10 +1334,6 @@ str      = STR_CONFIG_SETTING_STARTING_YEAR
 strval   = STR_JUST_INT
 cat      = SC_BASIC
 
-[SDT_NULL]
-length   = 4
-to       = SLV_105
-
 [SDT_VAR]
 var      = game_creation.ending_year
 type     = SLE_INT32
@@ -1486,11 +1436,6 @@ from     = SLV_77
 def      = true
 cat      = SC_EXPERT
 
-; previously ai-new setting.
-[SDT_NULL]
-length   = 1
-to       = SLV_107
-
 [SDT_OMANY]
 var      = script.settings_profile
 type     = SLE_UINT8
@@ -1665,13 +1610,6 @@ min      = 1
 max      = 255
 cat      = SC_EXPERT
 
-##
-; Used to be pf.opf.pf_maxlength & pf.opf.pf_maxdepth
-[SDT_NULL]
-length   = 3
-to       = SLV_REMOVE_OPF
-
-##
 [SDT_VAR]
 var      = pf.npf.npf_max_search_nodes
 type     = SLE_UINT