Enhanced check for auto-wielding

Consider martial art style and unarmed combat compatibility for
auto-wielding.

Rewrite player::get_combat_style to be much simpler (and const).

Force invlet to new wielded item on pickup, also display a message
when the pickup leads to wielding an item (already done in some
cases but not in all).

Made some functions const as needed.
Removed unused variable ma_styles, is now part of the player class.
Auto-wield refinement: check for unarmed skill even with selected style
Prevent blank lines from being written saved into options.txt
Only write untranslated string options (values/defaults) in options.txt because you can't set an option with the translated string.
Fixed Galens halfhearthed worldgen options implementation.
Modmanager: Display the mod description.
Not sure why they were here. Already done in options.h.
Add tooltip to worldgen options.
Unused code cleanup and braket styling.
Fixed spelling mistake: multible -> multiple
Minor drawing changes.
Autowielding: only when using a ma style.

New ma style: brawling, no special features.
New feature: aut-learn the brawling style upon level 2 in unarmed skill.
Add info to martial art selection menu.

A callback, triggered with the ? key shows a popup of the info of the selected style.
Export the styles usable by the bio_cqb into an array.
Also updates the help text for showing style information.
Removed call to strcmp, std::string will do the comparison. Also remove the lookup in the map using the ident just to get the ident.
Add game::ambient_sound

Ambient sound never cancels activities.
Made some existing sounds to ambient sounds.
Remove tabs, split strings without inserting new characters
Fix charges of toolset for disassembling broken_tankbot.

Also add the crude welder as alternative for disassembling broken bots.
Translation of motd and credits

Adds a function to load the whole credits/motd file and translate its contents.
The file content is automatically wrapped.
Add a function to the python script to extract the whole file for translation.

Removed the comments from the motd and credits file as they are outdated and wrong.
supplydrop: use number of created items instead of items on square

map::place_items returns the number of created items, use this instead of looking at target square. This works even when the items are actually placed on another square.
Also reduce the maximal number of placement attempts from 140 to 10.
Merge branch 'pickup-wielded-invlet' of https://github.com/BevapDin/Cataclysm-DDA into merge
Merge branch 'option-fixes' of https://github.com/OzoneH3/Cataclysm-DDA into merge
Merge branch 'martial_art-display' of https://github.com/BevapDin/Cataclysm-DDA into merge
Merge branch 'ambient-sound' of https://github.com/BevapDin/Cataclysm-DDA into merge