refine file version checking: based on https://github.com/bastimeyer/grunt-node-webkit-builder/commit/6331aad2e6501fb388de013d9bd8b52bba955756
Merge branch 'master' into develop

* master:
  node-webkit 0.10.0 version fix also on run
Fix and add a bit of error handling
Merge pull request #36 from 1j01/node-webkit-builder
Merge branch 'develop' into master