WIP: Editable ids

This PR makes editing of programme name, project name, property_code, device description and sensor type possible. It replaces sha-1 with uuid.

**BREAKING CHANGE:**

New PK for sensors is (device_id, sensor_id). When new device with sensors is created, the API returns device_id and map of readings with type and corresponding sensor_id e.g. 
```
{"location":"/4/entities/821e6367f385d82cc71b2afd9dc2df3b2ec5b81c/devices/1ab574e7-4f9f-4293-81b7-4f1e850e1aac","status":"OK","version":"4","readings":{"electricityConsumption":"16868e50-6363-4626-8043-392ac309f85f"}}
```
 Measurements have to be uploaded to device_id and sensor_id instead of device_id and type.
```
curl -v -H "Content-Type: application/json" -X POST -u username:password --data "{\"measurements\" : [{\"sensor_id\":\"16868e50-6363-4626-8043-392ac309f85f\", \"timestamp\":\"2014-05-12T10:30:00Z\",\"value\":\"0.5\"}]}" http://127.0.0.1:8010/4/entities/821e6367f385d82cc71b2afd9dc2df3b2ec5b81c/devices/1ab574e7-4f9f-4293-81b7-4f1e850e1aac/measurements/
```
Additionally, CSV with measurements have to contain Sensor UUID as a second row.

**MIGRATION:**

1. Database:
  ```
  cql/20141009_editable_ids.cql
  ```
2. Elasticsearch: 
  recreate schema using: 
  ```
  scripts/build-es-schema.sh
  ```
3. Copy existing sensor type to sensor_id column using:
  ```
  (use 'migrate)
  (migrate-types system)
  ```

Fixes #355 
Fixes #406 
Fixes #403