Added Collect/Save button; Found a bug in code; Made minor adjustments

Commented out the "Stop" button from main.xml -->
- GOAL: would be to have "Stop" button only visible while the Radar kit
is transmitting data to Android device running application.
- While "Stop" button is visible, "Collect" or "Collect/Save" button is
INVISIBLE!
- Only would be visible until..
--> application is done collecting data
--> button is clicked
- When finished collecting, the "Collect" or "Collect/Save" button
should reappear (set VISIBLE)

Add a new option (button) -> "Collect/Save"
- Starts collecting data and saves it perminently in File Archive
(- Other "Collect" option will only save the data in a temporary array
--> User can decide if they want to save it or not)

:: FOUND A BUG!! ::
--> "Save" button causes application to CRASH when it hasn't been sent
data from radar kit (currently another tablet) because the arrayDouble
(ArrayList<Double>) holds the most recent data sent to it.
--> ALSO ::
- Clicking the "Save" button only saves the data stored in arrayDouble
that was most recently "collected" from the other tablet
----> Hence, you can continue to load multiple files into the graph in
GUI, BUT the "Save" button continues to save the same collected data to
a new file.*

* Multiple files exist in the File Archive of the same data: not
processed, changed, or manipulated in anyway.
********* --> Should create a prompt to ask user if they want to
continue to store the same data again anyways *******

*** Save Button Purpose *****
--> The "Save" button should ONLY save what is currently plotted on the
GUI graph!!!!!
--> and obviously not <crash> when "accidently" pressed and there isn't
any data on the graph to save... and so on.

:)