Added nice looks to opening

Added a few pretty things to the opening screen.
1. When username or password are selected it highlights the whole text
(like yall asked :D )
2. Rounded the EditText's and Button's corners and changed the button's
color to red.
3. Added padding to the edges of the background so the EditText's and
Button are off the edges of the screen
If there is anything else you guys want me to try to add in the opening
screen let me know. I will do the game choice screen tomorrow.