Update default settings values

[LightArrowsEXE]

Updates the following label(s):

• PNG compression
  • Clarifies what the max value is

Changes the following values:

• Zoom levels
  • Use more sane zoom levels, doubling rather having semi-random values (50, 100, 200, 400, 800, etc.). Users who want those weird zooms can still set them themselves.
• Plugin panel position save
  • Default to "Local" (from: "No").