G_Variometer v7.8 patch

At first, this code is based on BlueFlyVario 0.61b.
Patch code is small range.
1. I cannot get current HW setting values of BlueFlyVario. So, I used a method of file saving & reading.
2. Pressure filtering is my own code because I have already my own code.
3. Finally, as I think this point is very important.
    When your own main activity get a pressure by sampling time(very short), handler is not good.
    I recommend using thread loop. In case of handler, there is many loss process sometimes
    (following phone maker). You have to use a direct commend like "public static void function()"
    for keeping sampling time.