Added harvest sprite for weeds.
Fixed seeds not showing up properly in the vendor.
Added portable_atmospherics to hydroponics machine path, couple of other tweaks.
Cleanup, adds setup parameters for atmos machinery

Allows atmos machinery efficiency to be adjusted in setup.dm
Limits flow rates when moving gas from a turf to avoid very high pressures being created when they shouldn't be.
Attempts to limit processing when there isn't much gas to be moved, for performance.
Reverts all changes to _gas_mixture.dm
Merge branch 'dev' of https://github.com/Baystation12/Baystation12 into hydroponics
Merge branch 'master' of https://github.com/Baystation12/Baystation12 into hydroponics
Merge remote-tracking branch 'upstream/dev' into power-net
A sensor which registers mechs and trains attempting to pass by and, if necessary, blocks their movement.

If enabled, detects mechs/trains and blocks their movement if they are coming from any of the directions set by dir. Can currently only be enabled/disabled by radio command and airlocks are updated to utilize this.

The current setup allows mechs to move through airlocks during normal cycles, which for example lets Odysseus out to save lives.
Once a shuttle docks however, the sensors are enabled to prevent boarding.

If blocked, players receive a simple message stating that their command has been overridden.
Generalizes pumping and filtering

So that people can pump and filter gasses without worrying about the
thermodynamics too much.
Updated body_parts_covered
Fixed issue with recognizing covered jumpsuit and gloves
Added dynamic flavour text, where covered bodyparts' flavour isn't displayed
Merge branch 'dev' of https://github.com/Baystation12/Baystation12 into flavourtext
Cleaned up mistake implementing dynamic flavour text
Merge pull request #5791 from PsiOmegaDelta/Roadblock

Mech/Train sensor
Updated changelog
Fixed issue with flavour text saving/loading from other characters
Optimizes atmos machine power updates

Makes power usage but atmos machinery less accurate but reduces lag
somewhat.
Adjusts power usage for R&D equipment
Installs the new mecha-sensor in the departure area airlocks and the shuttle itself.

Also corrects the online icon state for the sensor and allows the simple docking controller to toggle the on/off state.