Fresh start for v2
Rewrite core
Rewrite bin/busted to match core v2
Clean up style of specs and languages
Clean up setup and move `./src` to `./busted`

This allows one to use `bin/busted` to run without installing.
Zsh autocompletion
Implement tags
Add output handlers
Clean up remaining specs
Set up 2.0.rc0 version
Fix exit code and error output

Closes issues #252, and also fixes cases where bad syntax in tests would
cause the output handler to explode. Handles bad syntax gracefully now.
exit 0 or 1
Fix problem with table debug messages
Rewrite and simplify output handlers.
Clean up subscribers
Merge pull request #255 from Olivine-Labs/v2-output-handler-base

Rewrite and simplify output handlers.
2.0.rc1
Support for a helper (environment) script

Handy for preloading things prior to tests, etc
`.busted` was busted
Merge pull request #257 from nevir/patch-2

`.busted` was busted