Added BOM removal flag.

Byte order mark is now removed from the beginning of the files when b
flag is used.
Merge pull request #552 from blessenm/bom-precompilation-option

Added BOM removal flag.
Modify keywords type in package.json

`keywords` should be an array.
- https://npmjs.org/doc/json.html#keywords
Merge pull request #554 from tricknotes/modify-keyword-type

Modify keywords type in package.json