Made changes concerning the pressure readout elements.

- The average() method weighs each sample at 1/25th (4%) instead of 1/10th (10%).
- Removed unnecessary boolean.
- Modded the atm DecimalFormat.
- Instead of displaying text for the local average value, a progress bar is displayed.
- Declared a ProgressBar for use in the MainActivity.
- Replaced "Stable Indication" with simpler "Stable Readout".
- Removed ellipses in "One Moment..." string.
Code cleanup, optimization.

- Created Pressure class to handle everything related to that value.
- Removed average value calculation, it was terrible.