basic classes for server stuff
added ram tier 4 and 5 and adjusted textures
slots in computer cases are now tiered, closing #72.
Merge branch 'master' of https://github.com/MightyPirates/OpenComputers into 1.2
Merge branch 'more_ram' into 1.2

Conflicts:
	assets/opencomputers/textures/items/memory0.png
	assets/opencomputers/textures/items/memory1.png
	assets/opencomputers/textures/items/memory2.png
adjusted memory for tiered slots; adjusted settings for additional memory tiers and added compatibility check for older configs
recipes for additional ram modules, closes #69
Merge branch 'master' into 1.2
changed the way screen power consumption is computed. it's no only computed by the origin and no longer the actual number of pixels, but the relative number of pixels (based on the current resolution), with the cost being scaled based on the maximum resolution versus the resolution of the basic screen; screens can now be turned off to conserve power. turning them back on consumes as much energy as one cycle with a fully lit screen would, to avoid people trying to avoid the cost by turning screens off and on again at the right time (when the screen cost is actually computed, which doesn't happen every tick unless so configured - see power.tickFrequency)
made screens accept redstone signals; using redstone pulses on screens to turn them on or off (it's a toggle), closes #77
Merge branch 'master' of https://github.com/MightyPirates/OpenComputers into 1.2
Merge branch '1.2' into servers

Conflicts:
	li/cil/oc/Blocks.scala
	li/cil/oc/Items.scala
	li/cil/oc/common/GuiType.scala
post-merge adjustments
server item gui and inventory is working; fixed rendering of 3d items when in a gui with tiered slots
added two more tiers for cpus, since those will be used to control the number of components a server is able to address; server item texture and tooltips
added power buttons to server rack gui and sending and handling packet to toggle power
kinda got server racks doing stuff (once)
Merge branch 'master' of https://github.com/MightyPirates/OpenComputers into 1.2

Conflicts:
	li/cil/oc/Items.scala
Merge branch '1.2' into servers

Conflicts:
	li/cil/oc/Items.scala
	li/cil/oc/common/Proxy.scala
	li/cil/oc/common/tileentity/Computer.scala
Merge branch 'master' of https://github.com/MightyPirates/OpenComputers into 1.2