Add ability to handle conversion result data array
Passing multiple input files to converter

Usage: rex-cli.js -i /path/to/file1.xml,/path/to/file2.xml,... [...other_arguments...]

Now converter receives data in array like:
[
   { name: '/path/to/file1.xml', contents:<file1_content>},
   { name: '/path/to/file2.xml', contents:<file2_content>} .....
]
Merge pull request #3 from midik/patch-1

Passing multiple input files to & from converter