CSV upload

According to the API, user is able to remove ONLY own measurements (not cell towers!): http://www.opencellid.org/measure/delete/MEASURE_ID?key=API_KEY

2. Supported column names in uploadCsv method:

• lat
• lon
• mnc
• mcc
• lac
• cellid
• signal level
• create_at
• updated_at
• speed
• direction

Exported data has fields from our DB. Field 'samples' is a number of measurements, 'changeable' means if tower is calculated from measurements (True value) or is a precise tower (False value). Field 'averageSignalStrength' with 0 value is ok, because a lot of measurements don't have this signalStrength value and default 0 values is used.