Remove dest option, Add more tests from grunt-vulcanize

I've had few changes for #12:

- remove `dest` option
- options.output has been changed:
  - default: using same name of input file. in almost cases, user no need to set it if using a stream and gulp.dest
  - specific filename: it will be passed to vulcanize
  - filter function callback: If user want to handle a filename in multiple files
- Add more tests from `grunt-vulcanize`

Please let me know any problems or something strange. thanks.
`options.output` isn't a user option and should be handled for the user, as like before.