Add string for space key

It always looked a bit odd in the input manager when the space bar was assigned somewhere.
Add keybinding helptext to more menus

This commit adds a short help text for these menus to show the correct key to open the keybindings menu:
* Construction menu
* New character (first tab only)
* Overmap
Slightly more reasonable default keybindings

NEXT_TAB in character creation can no longer be done with TAB, because this is already used by gender,
so you could get stuck in the profession tab by switching tabs with TAB, which may be confusing.

Random names (character and world) are now using “*” instead of “?” to allow the keybinding menu to appear on “?”.
Show actual keybindings in world manager name tab
Cosmetic edit to default keybinding file

“SPACE” instead of “ ”, simply to be more consistent
Let the mod manager show the actual keybindings
Reserve world names “TUTORIAL” and “DEFENSE”
Use different font color for special saves

In this case, “TUTORIAL” and “DEFENSE”.
refactored season length calculation for consistency
Reload the *specific* item, not the weapon.

item::reload can be called for *any* item, even those in the inventory.
SDL: Add TARGETTEXTURE to the required rendered flags

Without this, SDL might chose a renderer that does not support rendering to a texture.
This makes SDL_SetRenderTarget fail later.
Make a dedicated draw_sidebar function:

contains all the stuff that is printed in the sidebar:
HP,
monsters,
mini map,
messages,
character status,
...
Added Finnish language
German update
riot control bot
Spanish update
Finnish update
Japanese update
Korean update
Russian update