ComputerCraft

* Added tab completion to "edit", "lua" and the shell.
* Added textutils.complete(), fs.complete(), shell.complete(), shell.setCompletionFunction() and help.complete().
* Added tab completion options to read().
* Added "key_up" and "mouse_up" events.
* Non-advanced terminals now accept both grey colours.
* Added term.getTextColour(), term.getBackgroundColour() and term.blit().
* Improved the performance of text rendering on Advanced Computers.
* Added a "Run" button to the edit program on Advanced Computers.
* Turtles can now push players and entities (configurable).
* Turtles now respect server spawn protection (configurable).
* Added a turtle permissions API for mod authors.
* Implemented a subset of the Lua 5.2 API so programs can be written against it now, ahead of a future Lua version upgrade.
* Added a config option to disable parts of the Lua 5.1 API which will be removed when a future Lua version upgrade happens.
* Command Computers can no longer be broken by survival players.
* Fixed the "pick block" key not working on ComputerCraft items in creative mode.
* Fixed the "edit" program being hard to use on certain European keyboards.
* Added "_CC_VERSION" and "_MC_VERSION" constants.