made the RIGID flag work for containers

Container without that flag add the volume of their content to the total volume of the item.
Container with that flag show just the containers volume and ignore the content.
fix waterskin2, should have different volume, not bash modi
Electronic cigarettes.
Removed unused code.
Specify that some e-cigs are disposable.
Add e-cigs to item groups.
Set turns_per_charge to 1 instead of 20, just in case - not sure if it's necessary.
Better description of advanced e-cigs.
option to change the language
More tweaks

Descriptions and moves Shaggy Fur direct from Lightly.  Should speed the
process and might knock down the sharing.
Fixes the prices of a few seasonings.
Merge branch 'master' of https://github.com/CleverRaven/Cataclysm-DDA into MutationTweaks
Fix typo

Fixes #7387.
Rename venoms

Fixes #7383.
Make ESC exit add/remove hotkey mode.

Add/remove hotkey modes are only partially modal. If you enter one of those
modes and press ESC, it would exit the help screen (or prompt you to save &
exit). With this change, ESC will leave the modal state instead. (Pressing ESC
again will have the same behavior of exiting the help display).
No empty strings in gettext
Improved error messages. Suppressed some json extract warnings
translation update
Use a display buffer for rendering

Render to a background texture, and only show the context of this texture when presenting the
Hoder tileset: set background tile "2" of the additional tiles of t_grass.

The grass foreground tile has transparent parts and those parts show the content of the previous frame in game.
Instead they should show the dirt under the grass (dirt has tile "2" and tile "2" is completely opaque).