More inheritance tweaks; simplify validations in `t` movement functions
Merge pull request #2 from eric-wieser/patch-1

Replaced i=1, #list with _, v in ipairs(list)
Overrides the built in API functionality
Not sure how that slipped in...
Merge pull request #4 from eric-wieser/master

Overrides the built in API functionality
Strip out file extensions from apis
API loading now works as intended

Apis can reference themselves with the `module` global variable. The module and environment are once again distinct, but environment access proxies to the module.
Added more error handling
Don't explicitly load files within an API
Add whitespace to betterapi.lua for legibility.
Merge pull request #5 from eric-wieser/betterapi
Add `betterapi` and `t` APIs to installer
Added an API to monkeypatch the turtle API to hold state.

Keeps track of position, orientation, and slot.
Could be extended to serialize and deserialize these.
Added simple programs that use the API
Merge remote-tracking branch 'damien/master'

Conflicts:
	apis/betterapi.lua
Merge pull request #7 from eric-wieser/dead-reckoner

Introduce some new programs and APIs to handle turtle navigation
Create simple tree farm script
Correct a mismatch between treefarm prompts and behavior
Add treefarm to list of default programs
Fix one last mix up between slots 1 and 2 in treefarm script