Test: Distance calculation.
Show sample points on plot view.  Fixed scale, not curvature consideration.
Remove padding.
Refactor: Better naming.
Calculated plot rect in m.
Plot fits to view.
Closer to correct aspect ratio, but still not perpendicular lines.
Offset drawing by view origin.

Conflicts:
	uk.co.tekkies.akko.groundstation/res/layout/activity_main.xml
Refactor: Tidy code.
Paint left and right sides differently.
Track LHS joystick down, down point and up.
Touch up detection improved.
Moved calculations out of onDraw()
Nailed: Left and right joystick up/down/position nailed.
Refactor: Remove unnecessary origin member.
Change: Colour joystick extent.
New: Limited touch coordinates to joystick extent.
New: Calculate joystick values.
New: Rectangular joystick extents. Ding: Round joysticks are quite limiting near the corners - you can't reach 1.0,1.0 due to the radius of the limit.
Change: Limit RHS by circle to limit combined euler angle.  Keep LHS rectangular - we want full range of both axis.