Fix 1096, 1131, 1828: Improve error messages for generated tokens

[xixixao]

Ok, here we go. Fixes #1096, #1131, #1828 and hopefully the hundred duplicates out there.

Pointing out errors not handled by this would be welcomed.

# Unexpected interpolation
    [stdin]:1:3: error: unexpected string interpolation
    {"#{key}": val}
      ^^
  # Implicit ends
    [stdin]:1:3: error: unexpected ,
    a:, b
      ^
  # Explicit ends
    [stdin]:1:4: error: unexpected )
    (a:)
       ^
  # Unexpected end of file
    [stdin]:1:3: error: unexpected end of input
    a:
      ^
  # Unexpected implicit object
    [stdin]:1:13: error: unexpected :
    for i in [1]:
                ^

[xixixao]

Maybe object literal or : causing object literal would be better, see the examples:

coffee -bpe '
foo:
  spaces: 2
    spaces: 4
'
[stdin]:4:11: error: unexpected :
    spaces: 4
          ^

coffee -bpe '
foo "a" b:1
'
[stdin]:2:10: error: unexpected :
foo "a" b:1
         ^

coffee -bpe '
object:
  a.property: "value"
'
[stdin]:3:13: error: unexpected :
  a.property: "value"
            ^

coffee -bpe '
{ a: 1
  b: 2 }
'
[stdin]:3:4: error: unexpected :
  b: 2 }
   ^

[jashkenas]

Bravo. Very neat approach of adding the origin.