Support ExtractTextPlugin and proper path resolution

* ExtractTextPlugin is supported by making the styleLoader configurable.
* The resolution of the bootstrap-path has been improved.
Addressed @petehunt code review

* Added logger function with option for verbose in config file
* Changed console.log to console.error for errors
* Used === for string comparison
* Fixed typo in README.md
Merge pull request #2 from justin808/support-extract-text-plugin

Support ExtractTextPlugin and proper path resolution