Changed player::has_active_item to use player::has_item_with.

Also removed inventory::has_active_item as it is not needed anymore.
Added documentation.
Prevent multiple item ids in standard_itype_ids.

Would have happened when a mod overrides the item definition.
Because standard_itype_ids is a vector, multiple entries with the same value are possible.
Content of items destroyed by acid get dropped separately.

Otherwise adding those items to the i_at vector invalidates the iterator.
this should fix the bug for loading the map a year later in the same
season, and the plant not being harvestable, but its not...
the submaps last_touched attribute is now when accessed.
this commit's point is to ask in github...
Create sheltered function
Fixed water temperature code
fixes the bugs spotted.
makes use of bitflags for performance optimization
MShock's v0.31

ref_lighter_on
socks_bowling
diamond_katana
diamond_knife
diamond_machete
newspapers
pine_bough
scarf_long
scarf_fur_long
pipe_tobacco
vp_frame_wood_horizontal_2
vp_frame_wood_vertical_2
t_door_b_peep
t_door_boarded_damaged
t_door_boarded_damaged_peep
t_door_boarded_peep
t_door_c_peep
t_door_locked_peep
t_door_o_peep
t_pit_glass_covered
f_large_canvas_door
f_large_canvas_wall
f_large_groundsheet
f_rubble_rock as f_rubble for now
assigned all brew_, beet_syrup
tweaked t_sandbox
tweaked t_wall_tcon
tweaked background for met. wall
fixed apricot tree
For mods:
t_little_column
t_gas_pump_a
gasdiscount_
hand_paddles
hand_pump
Merge branch 'seasonal-fruit-trees' of https://github.com/jcd000/Cataclysm-DDA into merge
Merge branch 'tileset' of https://github.com/Mshock777/Cataclysm-DDA into merge
Merge branch 'bugfixes' of https://github.com/BevapDin/Cataclysm-DDA into merge
Special attack timeout function creation
Added some second specials
Fixed a comment.
Merge branch 'quick-worldfactory-comment' of https://github.com/mafagafogigante/Cataclysm-DDA into merge
JSON patch-job

No big deal, I've made copy-paste errors too.
Merge remote-tracking branches 'dda/pr/9393', 'dda/pr/9425' and 'dda/pr/9435' into dda-master

* dda/pr/9393:
  Changed player::has_active_item to use player::has_item_with.
  Move reduce_charges from inventory into player class.
  Move has_gun_for_ammo into the player class.
  Extract check for LITCIG into a helper function.
  Removed inventory::watertight_container
  Removed player::max_active_item_charges
  Removed inventory::has_liquid
  Removed player::i_of_type
  Removed player::i_rem(typeid)
  Use generic function for has_item / remove_item in player and inventory class.
  Move inventory::all_items_with_flag into the player class
  Change player::remove_mission_items to be compatible to player::has_mission_item
  Use generic item-find function for player::has_mission_item
  Replace player::has_drink and inventory::all_drinks with generic filter function
  Implement a generic player::remove_items_with function.
  Implement generic templated item-in-player-possession functions.
  Add const to some methods, comparing a const item pointer is fine.

* dda/pr/9425:
  Made overmap file independent of the game mode.

* dda/pr/9435:
  Removed repeated code.
Makes sandwiches stop heating themselves up.

Fixes https://github.com/CleverRaven/Cataclysm-DDA/issues/9442.
Fixes price of the RM42 knife.
Make item weights apply to all the furniture dragging calculations.