1.4.0
New features:
* Enable to automatically add a unique ID to each zone before aggregating losses
by zone
* Manage multiple project definitions for each layer
* Enable to invert variables through the project definition
* Import multiple csv files exported by the OpenQuake Engine and build a loss
layer from them (plus tests)
* Maintain QGIS style when uploading a project to the OpenQuake Platform
* Improved look&feel and refactoring in the javascript GUI
* Added tests for data aggregation
* Added plugin's main icon