Gravity Generator

- Addition of Gravity Field Generators
- Added animation for when floating
- Toggle Gravity in Secrets menu only works when a Grav Gen is on the
station
- New debug verb to reset the gravity on the whole server

Because of the way this has been implemented, any Grav Gen on any zLevel
will affect the station level only. I would need to rewrite the whole
movement/gravity system as well.
Something I think can be saved for when we switch from station to
outpost.

Mapping info:
At the start of round there doesn't need to be one on the station as the
original gravity system will be running when the round starts.  As soon
as a Grav Gen has been spawned and it has started up (Done automatically
if already on map or spawned using the /station/admin version) It will
take over all gravity simulation.

The main object:
/obj/machinery/gravity_field_generator/main

The one to be place on a map at round start:
/obj/machinery/gravity_field_generator/main/station

The one admins should spawn if they need/want to spawn one:
/obj/machinery/gravity_field_generator/main/station/admin
Merge pull request #1 from SoundScopes/development

Gravity Generator
Forgot rename

Rename didn't stick
Merge pull request #190 from SoundScopes/master

Gravity Field Generators
Merge pull request #1 from Aurorastation/development

Development
Hazmat Suits

Replacements. Need to work on more.
Map Update 25JUL2014

Disposals, misc errors, gravity generator.
Merge pull request #191 from skull132/master

Map and Biosuits
Merge pull request #192 from Aurorastation/development

Update 25JUL2014