[Frontier] The bounded area is defined in meters (double)

While here, remove undesired markup (used for folding).
[Frontier] Fix the validity of the seed value.

A seed outside of the bounded area is still valid.
And the weight map and the raster have their own way to manage
value outside the image. (throw exceptions)

While here, remove some too verbose output and try to respect the 80-char length
of the code.