Adds simple peanuts to hydroponics

Thanks to Nienhaus for the sprites.
http://baystation12.net/forums/viewtopic.php?f=44&t=9984
Will update this with more applications for peanuts soon.
Adds Meyar's , Serithi's and Ikky's items

Adds 3 approved custom items.
http://baystation12.net/forums/viewtopic.php?f=33&t=9776
http://baystation12.net/forums/viewtopic.php?f=33&t=10197
http://baystation12.net/forums/viewtopic.php?f=33&t=10265
say_understands() fixes and cleanup.

Whether or not someone can understand a language is now handled entirely
by the language check in mob/say_understands(). The way the old code was
written makes me think it came before languages were implemented.
Derp, forgot speaking parameter.
Moved silicon/say_understands() to silicon/say.dm
Adds languages for AI
Adds languages for robots
Adds languages for pAIs

Left universal translator as-is.
Silicon mob types can now speak languages
Added speech synthesizer list for silicon mobs
Whisper now supports languages
Removed verb assignment from hear_say()

This gives more control over the verb to procs that use hear_say(). Also
they were already assigning the language specific verbs to begin with.
Adds non-verbal languages
Adds Siik'tajr
Fixed paths

Woops.
Primitive mask icon_state fix

Why so up?
Removed reappearing icon_state

Alright, I think this PR is finally fixed.
Adds 50_n00b's approved custom item.

Alright, this one shouldn't have any issues.
Adds Serveris's custom item

http://baystation12.net/forums/viewtopic.php?f=33&t=9992
Fixes language_keys not initialized correctly

Also prevents speech ending verb from overriding language verb for
humans.