Pass file name to traceurRequire to give better error messages.

Adds test for error and its content.
Fixes #1380 using the sugegstion of @spadgos

Review URL: https://api.github.com/repos/google/traceur-compiler/issues/1383

Closes #1383, closes #1380.
Enforces end-of-line to be LF on Windows

Fixes #1392

Relates to #235
Fix issue with block binding in unbraced for

When transforming the body for if, for, while, do and with, where
either a Block or a single statement is allowed we need to convert
AnonBlocks to normal blocks.

The code for this is generated by the code gen. We use the type
`Block | ParseTree` as the type to trigger this code path.

Fixes #1381