Fixes in order:
- Removes List of defines in misc_ch.dm that are no longer used - they're defined here for the casino prize dispenser, making these obsolete:

- Fixes relative pathing in mecha_parts_ch.dm
- Fixes relative pathing in bodybag.dm
- Fixes relative pathing in sahoc_ch.dm
- Fixes relative pathing in toys_yw.dm
- Fixes def_zone being defined when only the variable was needed in twohanded_ch.dm
- Fixes relative pathing in trash_pile_vr_ch.dm
- Fixes clip_mask being missing in misc_ch.dm
- Fixes relative pathing in tesh_synth_facemask.dm
- Fixes absolute path being indented in by one (typo?)
- Fixes relative pathing in armor_yw.dm
- Fixes unreachable parent call in audible_scream_ch.dm
- Fixes VERM_LIZARDS being undefined when it wasn't defined, as VERM_LIZARDMEN was the variable being defined + used in mutants.dm
- Removes two un-needed parent calls - these procs have no parent on /obj/structure - thecake_ch.dm
- Fixes invalid kword nano_state in protean_blob.dm
- Fixes relative pathing in drone_manufacturer_unify.dm
- Fixes relative pathing in synx.dm
- Removes arguments of drop_item that don't exist (port was from TG and had force_drop = 1 and src defined.) - vox.dm
- Added vision_required = TRUE to fix proc argument missing - bigdragon_ch.dm
- Added include_robo = TRUE to fix argument missing in demon_ch.dm
- Fixes relative pathing in rakshasa_abilities.dm
- Adds comment to solargrub.dm, unable to fix operator overload error yet.
- Fixes relative pathing in sprite_accessories_extra_ch.dm
- Fixes relative pathing in sprite_accessories_yw.dm
- Fixes relative pathing in phase.dm
- Fixes relative pathing in bluespacecoffee.dm
- Fixes relative pathing in other_ch.dm
- Fixes relative pathing and ambigious ! in living_ch.dm
- Fixes relative pathing in custom_clothes_yw.dm
- Fixes relative pathing in custom_rigs_yw.dm
- Fixes relative pathing in MadokaSpear.dm
- Comments out duplicate #includes in southern_cross.dm as vorestation.dme has them #include'd.
A lot of new defines are now in inventory_sizes.dm, which contains;
All the size identifiers (the thing that tells the game if something is bulky, or w/e).
Storage costs for all the sizes, which are exponents of two, as previously.
A few constants for inventory size.
Also changes all storage item's capacity definitions by basing it off of how many 'normal slots' exist for it. This allows one to change the definition for all of the defines in the file, and everything will follow along without needing to change 500 files. In testing, I made all ITEMSIZE_COST_* defines doubled, and nothing had broke.
The benefit of doing all of this is that it makes adding new weight classes in the future much simpler, and makes knowing how much space a container has easier, as seeing ITEMSIZE_COST_NORMAL * 7 means it can hold seven normal items.
Freezer crates, freezer boxes, cryobags, and medical grippers now properly preserve organs, as well as organs attached to organs.
Cleans up storage.dm slightly by removing loc setting with forceMove(), for the above to work.
Merges the use of the is_small and mob_size into one.
Changes the species size handling to set the mob size instead of being yet another separate var to check.