found a linear shift of lineno, dirty patch for now

It seems that js -> coffee line mapping has a linear shifting.
Dirty patch by applying linear correction.
Dumb, but maybe a hint.
Apply modifications by @jwalton
Improve literate mode.

* Expect a blank line as delimiter between text and code (#2821).
* Don't change indentation of code. It is not necessary and leads to
  erroneous locationData. (#2835)
* Don't modify blank lines and reverse the change in the lexer.
* Don't ignore indentation with mixed whitespace.
Test case for literal mode: Code blocks must be preceded by blank line.
Compiled JavaScript files for improved literal mode.
fix path handling on Windows
Fixes #2555
whitespace
Fixes #2478 -- mention js2coffee in docs
fixed lineno