Additional publicdata measures

[GP8x]

Extended the GetPublicData API to support the following measures in addition to rain:

• temperature
• pressure
• humidity
• wind_strength
• wind_angle
• wind_timeutc
• gust_strength
• gust_angle

This PR renames all the API methods in this file to indicate the measure they are retrieving although have retained the original getLive(), get24h(), get60min() and getTimeforMeasure() for backwards compatibility.

This PR also splits the measures into two distinct types "station" and "accessory" - station indicating they come from the original Netatmo weather station and accessory to indicate they come from either the rain or anemometer units. This is important as the data returned in the GetPublicData API is different. e.g:

{
    'res': {
        '1536357836': [12.7, 63]
    },
    'type': ['temperature', 'humidity']
}

compared to:

{
    'rain_60min': 0,
    'rain_24h': 0.101,
    'rain_live': 0,
    'rain_timeutc': 1536357829
}

Additionally, the wrapper now includes methods to get a single average value for each measure to ease end users who just want a simple way to get a single value for an area. The only exception to this is the wind/gust angle measures - the data is not clean enough for an average to be useful.

Bumped to version 1.2 to indicate the additions but no API changes.

p.s. HomeAssistant fans - The whole purpose of this PR is so that I can extend the support of the new Netatmo Public Sensor :)