tests implemented
schema changed
added stddev_loss to writers
Some renaming and a small fix on the streaming writer
Merge pull request #104 from matley/std-losses

Add stdDevLoss field
Added Readers and improved the error message of assert_valid
Added an InvalidFile exception
Merge pull request #105 from gem/InvalidFile-exception

Added an InvalidFile exception
Merge branch 'master' into csv-tools
Saved the .json in indented form
Added the NRMLconvert tool, first version