simplified callback syntax

[rzimmerman]

Something like:

name = "Steve"
db.findByName name yields user
console.log user.id

Instead of:

name = "Steve"
db.findByName name, (err, user) ->
  return err if err
  console.log user.id

[rzimmerman]

The yield branch is tracking this feature.

[rzimmerman]

Merged in yield branch at 00c490fb1b2ca3d7437ef982b56ad33d79486d0f

This supports (possibly buggy) the following syntax:

wait for x from slowIoFunction()

for:

• Basic callbacks
• Nested callbacks
• Callbacks in conditionals (ifs)
• Error handling

But not loops yet

[rzimmerman]

Merged in all changes, passing tests. Any further fixes should be logged as new issues (bugs): 1db530a6ecb83e17ccac88b33ea535f1d9c95174