Remove reference to g->m from map functions

Those functions will use the implicitly given `this` object now.

Always using the main game map is redundant at best (as the function will typically be called on the main game map anyway, so `this == &g->m`).
But it may in fact be wrong: e.g. when the functions are called on a temporary map (e.g. during mapgen).

src/map.cpp

@@ -838,7 +838,7 @@ void map::register_vehicle_zone( vehicle *veh, const int zlev )
 
 bool map::deregister_vehicle_zone( zone_data &zone )
 {
-    if( const cata::optional<vpart_reference> vp = g->m.veh_at( g->m.getlocal(
+    if( const cata::optional<vpart_reference> vp = veh_at( getlocal(
                 zone.get_start_point() ) ).part_with_feature( "CARGO", false ) ) {
         auto bounds = vp->vehicle().loot_zones.equal_range( vp->mount() );
         for( auto it = bounds.first; it != bounds.second; it++ ) {
@@ -2934,7 +2934,7 @@ void map::smash_items( const tripoint &p, const int power )
     }
 
     std::vector<item> contents;
-    auto items = g->m.i_at( p );
+    auto items = i_at( p );
     for( auto i = items.begin(); i != items.end(); ) {
         if( i->active ) {
             // Get the explosion item actor
@@ -4378,7 +4378,7 @@ item &map::add_item( const tripoint &p, item new_item )
     }
 
     if( new_item.is_map() && !new_item.has_var( "reveal_map_center_omt" ) ) {
-        new_item.set_var( "reveal_map_center_omt", ms_to_omt_copy( g->m.getabs( p ) ) );
+        new_item.set_var( "reveal_map_center_omt", ms_to_omt_copy( getabs( p ) ) );
     }
 
     current_submap->is_uniform = false;
@@ -4401,7 +4401,7 @@ item map::water_from( const tripoint &p )
         return item( "salt_water", 0, item::INFINITE_CHARGES );
     }
 
-    const ter_id terrain_id = g->m.ter( p );
+    const ter_id terrain_id = ter( p );
     if( terrain_id == t_sewage ) {
         item ret( "water_sewage", 0, item::INFINITE_CHARGES );
         ret.poison = rng( 1, 7 );
@@ -4633,7 +4633,7 @@ void map::process_items_in_submap( submap &current_submap, const tripoint &gridp
         const tripoint map_location = tripoint( grid_offset + active_item_ref.location, gridp.z );
         // root cellars are special
         temperature_flag flag = temperature_flag::TEMP_NORMAL;
-        if( g->m.ter( map_location ) == t_rootcellar ) {
+        if( ter( map_location ) == t_rootcellar ) {
             flag = temperature_flag::TEMP_ROOT_CELLAR;
         }
         map_stack items = i_at( map_location );
@@ -5591,7 +5591,7 @@ basecamp map::hoist_submap_camp( const tripoint &p )
 
 void map::add_camp( const tripoint &p, const std::string &name )
 {
-    tripoint omt_pos = ms_to_omt_copy( g->m.getabs( p ) );
+    tripoint omt_pos = ms_to_omt_copy( getabs( p ) );
     basecamp temp_camp = basecamp( name, omt_pos );
     overmap_buffer.add_camp( temp_camp );
     g->u.camps.insert( omt_pos );
@@ -5737,7 +5737,7 @@ void map::draw( const catacurses::window &w, const tripoint &center )
     g->reset_light_level();
 
     update_visibility_cache( center.z );
-    const visibility_variables &cache = g->m.get_visibility_variables_cache();
+    const visibility_variables &cache = get_visibility_variables_cache();
 
     const auto &visibility_cache = get_cache_ref( center.z ).visibility_cache;
 
@@ -8490,8 +8490,8 @@ std::list<tripoint> map::find_furnitures_in_radius( const tripoint &center, size
         size_t radiusz )
 {
     std::list<tripoint> furn_locs;
-    for( const auto &furn_loc : g->m.points_in_radius( center, radius, radiusz ) ) {
-        if( g->m.furn( furn_loc ) == target ) {
+    for( const auto &furn_loc : points_in_radius( center, radius, radiusz ) ) {
+        if( furn( furn_loc ) == target ) {
             furn_locs.push_back( furn_loc );
         }
     }