Add bars to set number of samples to get average presure (non functional).

Added bars for start presure and current presure.

Signed-off-by: Janusz Kozerski <janusz.kozerski@gmail.com>
Add bars to set number of samples to get average presure (done).

Added bars for start presure and current presure.

Signed-off-by: Janusz Kozerski <janusz.kozerski@gmail.com>
Add Button to reset to default number of samples.

Button reset to the default number of samples to calculate the
average presure value, and fix the selected position on bars.
The default values are:
 * for start presure - 16 samples (no changed)
 * for current presure - 8 samples (was 4).

Signed-off-by: Janusz Kozerski <janusz.kozerski@gmail.com>