feat(restful): prepare resources "/api/accouts", "/api/iec_meters", "/api/electricity" to works with the client application.

#47 
method GET
![screen shot 2014-10-26 at 4 39 35 pm](https://cloud.githubusercontent.com/assets/2622152/4783261/e24537e4-5d1e-11e4-88d3-519eb6832486.png)

@shahardo Could i overwrite the existing csv file, to change the date format to timestamp? and fix in a next issue? 

https://github.com/Gizra/negawatt-server/blob/acb914e942136e4865ade99ce87920bde8b89c82/negawatt/modules/custom/negawatt_migrate/csv/electricity/electricity.csv